Anderson Brown's Philosophy Blog

Aristotle and Wittgenstein

2011-11-11T13:38:00.001-04:00

I’m afraid that some readers will be growing impatient as they read the foregoing discussion of a kind of Platonic resolution to the problem of rationality. Hadn’t I just, in the first half of this same chapter, argued for an operational theory of intentional predicates? Not only that, but when one suggests that the non-physical property of “meaning” can be washed out of the ontology of mind and language (replaced with an externalist account of intentional predicates as describing relations between persons and environments), that would be about as nominalist as one could go, surely? Maybe not. The Platonism that I am offering has only one element of basic ontology besides matter. Form is indivisible, not divisible; a unity, not a multiplicity. There is only one form really: only one (perhaps inexplicable) ontological fact beyond the fact of the existence of something rather than nothing. Putting the question of Plato and Aristotle’s own views of species as “fixed natural kinds” to the side in favor of a view of species informed by evolutionary biology, it can be seen that putative “forms” such as the property of “cowness” or “lyrehood” are not genuine examples of form. Some categories (types of species, types of artifacts) come-to-be and pass away. In its Aristotelian version Platonic form-matter dualism becomes a kind of non-reductive materialism: primary being is substance, the unity of form and matter. From the doctrine of the unity of form, though, it appears that this must be a kind of “non-reductive formalism” as well, as every particular with a formal property has that property, not by virtue only of the formally-organized parts of that particular, but by virtue of the entire formal organization of the material world: all geometric shapes (for example) are tokens of the one thing. We know that by this point Wittgenstein would be fuming, but as usual with him we might not be certain exactly why. Of course Wittgenstein would have none of this Platonic talk. “The idea that in order to get clear about the meaning of a general term one had to find the common element in all its applications has shackled philosophical investigation; for it has not only led to no result, but also made the philosopher dismiss as irrelevant the concrete cases, which alone could have helped him to understand the usage of the general term. When Socrates asks the question, ‘what is knowledge?’ he does not even regard it as a preliminary answer to enumerate cases of knowledge.” (Blue and Brown Books; italics in original). Wittgenstein’s operationalist account of functional-role semantics is an arch-nominalist position: there is human behavior, a highly-adaptive and plastic process that changes over time, whose constants are determined by the biological (probably the best choice) nature of the human body and the human “mode of life.” “Property” names (like all names) really pick out parts of language, and the criteria for the proper application of language are essentially operational. Insofar as this line is developed as a strategy to naturalize meaning I think it’s a good one. But I have never thought that philosophy of mathematics was a particularly strong point for empiricists, and that is troubling considering that Wittgenstein devoted a considerable portion of his writings to the development of an operationalist theory of mathematics. In any event I am unpersuaded by Wittgenstein’s view that extending the known proofs of mathematics is nothing more than an elaboration of a kind of “language game,” specific to humans by virtue of our particular “form of life,” such that there was no such system of entailments until some human (for example) elaborated it. It’s counterintuitive: isn’t the fact, that we can work our way from one part of mathematics to another, evidence that mathematical reasoning is coherent? Doesn’t Wittgenstein’s ultra-nominalist view of mathematics overstate the possibility space: the different ways “mathematics” could go? However, it may be that the two treatments of the two different parts of intentionality - an eliminativist, operationalist argument to the effect that mental representation/content is not part of the reference of intentional predicates, on the one hand, and an Aristotelean argument to the effect that rationality is nothing more nor less than a formal property and that formal properties, if they exist at all, are ubiquitous – are compatible. According to Wittgenstein there are no abstract entities, of course, but it is important to appreciate how far Wittgenstein went in his naturalization of meaning, and how central to this were his ideas about mathematics. Wittgenstein saw mathematical behavior as a “technique,” a technique for living. “Living” is the operational verb that replaces the Cartesian verb “knowing”: a case of knowing how rather than knowing that. Wittgenstein rejected the passivity of the representational theory and insisted on viewing language as a physical behavior that aimed at getting on with the business of life. Granted that the Aristotelean world is one where every concrete particular is a union of matter and form, the “form of life,” understood as the vital activities of a being of that kind, would exhibit formal properties. In fact “behavioral ecology” develops an entire narrative, largely mathematical, about the ratio of nutrients per square meter to species population per square meter, showing the correlations between these functions and genetic transmission and so forth. The human “form of life,” if it is anything at all, is a product of the same natural history as that of the human organism; the rationality of humans, like the harmony of musical instruments, is an expression of form. Within this form of life, that stress made no more emphatically by anyone than Wittgenstein himself, the criteria for use of psychological predicates can be understood operationally such that no mental content is implied. In fact Wittgenstein and Aristotle come together in a sense around “form of life” or what Aristotle would call the telos of an organism. They both suspected that explanations about what sort of thing a thing was and what sort of life a thing led were more informative than explanations about what sort of things a thing thought. Wittgenstein thought that the notion of mental content made no sense. I take the argument from the form-matter distinction to show that “computation” need not necessarily entail mental representations; organizational complexity equivalent to the syntactical complexity of language is found throughout nature. Finally, Wittgenstein’s functional-role semantics and Aristotle’s teleological account of biological explanation are very similarly motivated. They come together in the area where functionalism replaces reductive materialism as a response to the supervenient nature of the functional property.

The Mereological Fallacy and representational Theories of Mind

2011-10-09T15:20:00.000-04:00

Stomachs don’t eat lunch. Eating lunch is something that a whole, embodied person does. We understand the role that stomachs play in the lunch-eating process; we appreciate that people can’t eat lunch without them. Brains don’t think. They don’t learn, imagine, solve problems, calculate, dream, remember, hallucinate or perceive. To think that they do is to commit the same fallacy as someone who thought that people can eat lunch because they have little people inside them (stomachs) that eat lunch. This is the mereological fallacy: the fallacy of confusing the part with the whole (or of confusing the function of the part with the telos, or aim, of the whole, as Aristotle, who as usual beat us to the crux of the problem, would say). Nor is the homunculus a useful explanatory device in either case. When I am asked how we might explain the workings of the mind without recourse to mental representations (students often ask this), the reply is that we fail to explain anything at all about the workings of the mind with them. “Remembering my mother’s face is achieved by inspecting a representation of her face in my mind.” This is explanatorily vacuous. And if reference to representations does nothing to explain dreaming, imagining and remembering, it is particularly egregious when mental content is appealed to for an explanation of perception itself, the original “Cartesian” mistake from which all of the other problems derive. A person is constantly developing and revising an idea of his or her world; you can call it a “picture” if you like (a “worldview”), but that is figurative language. A person does not have a picture inside his or her body. Brains don’t form ideas about the world. That’s the kind of thing people do. This original Cartesian error continues to infest contemporary cognitive science. When the brain areas in the left hemisphere correlated with understanding speech light up and one says, “This is where speech comprehension is occurring,” the mereological fallacy is alive and well. Speech comprehension is not something that occurs inside the body. Persons comprehend speech, and they do it out in the “external” world (the only world there is). Positing representations that exist inside the body is an instance of the mereological fallacy, and it is so necessarily, by virtue of the communicative element that is part of the definition of “representation,” “symbol” etc. Neither any part of the brain nor the brain or nervous system considered as a whole interprets anything. The key to developing a natural semantic of intentional predicates is to realize that they are predicated of persons, whole embodied beings functioning in relation to a larger environment. Brain/body dualism can be presented as non-dualist (isn’t the brain a physical organ of the body?), but it is an insidiously Cartesian view that gets us no farther in naturalizing intentional predicates.Suppose that you are driving down the freeway searching for your exit, and you’re worried you might have passed it. You remember that there are some fast-food restaurants at the exit, and you think that one always feels that they have gone too far in these situations, so you press on, keeping an eye out for the restaurants. However you manage to do this, it is no explanation to say that you have done it because your brain remembered the fast-food restaurants, and has beliefs about the phenomenology of being lost on the freeway, and decided to keep going and so forth. That’s like saying that the way you had lunch was that your stomach had lunch. This realization may also be momentous for brain science. Go to the medical school bookstore, find the neurophysiology textbooks and spend a few minutes perusing them. Within the first minutes you will find references to the “movement of information” (for example by the spinal column), “maps” (for example on the surface of the cortex), “information processing” (for example by the retina and in the visual cortex) and so on. (Actually my impression is that brain scientists are relatively sophisticated in their understanding of the figurative nature of this kind of language compared to workers in other areas of cognitive science; the point is just that representational talk does indeed saturate the professional literature through and through.) But if brain function does not involve representations then we don’t know what brains actually do, and furthermore the representational paradigm is an obstacle to finding out: think of all those experimentalists developing protocols to try to “locate the symbolic architecture.” They might be looking for something that isn’t there. If there is any possibility that this is true these arguments need to be thoroughly explored at the very least.Taking the argument from the mereological fallacy seriously also draws our attention to the nature of persons. It follows from what has been said that the definition of “person” will be operational. Operational definitions have an inevitably circular character: a person is any being that takes intentional predicates. In fact there is not a “machine-language” explanation of personhood. Kant, writing in the late 1700s, is fastidious about referring to “all rational beings,” he never says “human beings”; he understands that when we are discussing the property of personhood we are discussing (what I would call) a supervenient functional property (Kant would call personhood “transcendental”), not a contingent physical property. However Kant is programmatically intent on limiting the scope of materialism as such and thus fails to develop non-reductive materialism. Instead he imports the mental (“reason”) from the noumenal world and ignores the problem of the relationship between transcendental reason and the human body (this is not to say that he does not acknowledge the role of our particular, contingent sense organs in shaping our representations of the world to the extent that those representations are themselves contingent and particular to us). With Kant we remain in our bodies but not of them.Once one recognizes that intentional predicates are predicated of whole persons – once one sees that positing mental representations necessarily commits the mereological fallacy – the question of representation is settled. It is I, and not some “brain state,” that is remembering my mother’s face. However there is a tight network of arguments and assumptions, centered on a model of intentional states as “propositional attitudes,” that will have to be disentangled to the satisfaction of readers who are disposed to defend representations. After that unpacking is done the reader will also reasonably expect some account of a non-representational analysis of intentional predicates, something that is not achieved by simply pointing out the mereological fallacy.

A Short Introduction to the Philosophy of Artificial Intelligence

2011-06-19T10:56:00.002-04:00

This is a rough draft, I participated in an interdisciplinary class and I'm thinking of submitting to maybe "Teaching Philosophy."

I. The historical background

AI is not only a rich source of new technology produced by interdisciplinary syntheses. It also, in its theoretical component, is an extension and elaboration of some of the central, canonical debates about “intelligence,” “mind” and “rationality” that have defined philosophy and psychology for hundreds of years. Specifically we find ourselves participating in the conversation that dates back to the “Early Modern” period of philosophy, roughly the 17th and 18th centuries, between so-called “Rationalists” (Descartes, Spinoza, Kant) and so-called “Empiricists” (Locke, Berkeley, Hume). The Rationalists, impressed by humans’ apparently unique ability to formalize mathematics and logic, held that the human mind was endowed with innate abilities and knowledge, and that these abilities could not be understood using the methods of natural science (these views were anticipated by Plato). The Empiricists of the 18th century Enlightenment, eager to develop a naturalistic account that integrated humans into nature, proposed a simplified psychology that essentially saw the mind as a learning machine and concentrated on perceptual psychology and learning theory. (Nowadays historians of philosophy tend to see the Rationalist/Empiricist distinction as a bit overstated, as we can see in perspective that they were all discussing the same set of issues with many of the same premises.)

An important product of this Early Modern discussion, introduced by Descartes in the first half of the 1600s (Descartes 1637) but crystallized by Kant at the end of the 1700s (Kant 1789) was the representational theory of mind. According to this view the mind works by constructing a representation of the world; Kant developed the idea of a

“conceptual framework” such that our “picture” of the world was as much a product of our own innate mental structure as it was of our perceptual experiences. Thus the issue of mental representation is an essential issue in the elaboration of the nativist/learning theorist divide as it plays out across the 19th and 20th centuries. For example, the behaviorists of the early 20th century are nothing neither more nor less than Humean empiricists: they applied “operationalist” ideas from the philosophy of science to try to develop a psychology that was cleansed of any reference to unobservable, “internal” mental “states,” including representations (mental content). On the other side the phenomenologists of the same period advanced the thoroughly Kantian argument that the study of the structure of experience would always necessarily stand apart from physical science. (Here we can stop and notice an even deeper root: the medieval question of the duality of the body and the soul.) In the middle of the 20th century the “nature/nurture” debate, as this same set of issues was then called, was of central importance in debates about the social sciences in general, a central battleground of the “culture wars” of the 1960s and 1970s. The nativist/learning theory divide also shaped the 20th century ethological literature about the mental lives of non-human animals.

II. Computation and representation

The issue of representation is central to contemporary debates about models of computation. In fact the theory of computation is yet another version of the same argument that constitutes the theory of the social sciences and the theory of ethology. Alan Turing in 1936 introduced his “Turing machine,” a thought-experiment that showed that a simple machine could instantiate any algorithm of mathematics and logic. This was a seminal moment not only in the development of computers but also in the course of artificial intelligence research. For the next fifty years many in the cognitive science community and the public at large saw “artificial intelligence” as just synonymous with computer science. Two crucial points here: first, to understand what is happening in artificial intelligence research today it is necessary to understand the computationalist era, because what we are currently living through is a departure from that era. Second, computationalism, as conceived by Turing and others, required representation: classical computation is rule-governed symbol-manipulation.

At this point we can consider some basic premises of linguistics. The classical computationalist view reached its apotheosis in 1975 with the publication of Jerry Fodor’s The Language of Thought. Noam Chomsky had launched what seemed for a time a devastating attack on behaviorism with his critique of B. F. Skinner’s 1957 book Verbal Behavior and Chomsky’s subsequent Aspects of a Theory of Syntax (1965). Chomsky argued that a syntactical structure (a grammar, or set of rules for constructing sentences and statements) was generative (it could generate novel linguistic representations and therefore novel thoughts), and was thus necessary for higher-order thought (this argument led to the sign-language research with chimpanzees of the 1960s-80s). This was, as Chomsky himself stressed, Cartesianism in a new bottle.

Fodor applied these ideas to cognitive science in general. Any representational theory of mind requires a symbolic architecture: this is simply the material instantiation of the symbols: the pixels in the computer screen, the ink marks on the page, the sound-compression waves caused by vibrating vocal chords, the chalk marks on the board. If the nervous system is a symbol-manipulating system then there must be a material instantiation of the symbols as part of the physical structure of the system. Fodor proposed that syntactical structure (the program, if you will, of the brain) could account for the causal role of the seemingly semantic mental content. This arch-computationalist view took it as axiomatic that the mind/brain necessarily involved representations.

III. Computers and the brain

Computers are our own creations, so their workings are not mysterious to us. The same thing cannot be said of the brain. Each age draws on the current technology as a metaphor/theory about how the brain works: the 17th century physicalist Thomas Hobbes, for example, drew heavily on hydraulics in his discussion of the mind. He speculated that memory might be a kind of vibration, as in a spring, that lost coherence as other vibrations passed through. In our time it is commonplace to speculate that the brain is a kind of computer and that a computer is a kind of a brain. However there are two very different approaches to developing this idea.

Classical computation is based on codes (programming languages) that contain explicit instructions for the transformation of states of the machine. The actual “machine language” is binary code (this is the meaning of “digital”). The symbolic architecture in a traditional computer is located in the “chip.” This is a series of gates that might either allow or block an electrical impulse to pass through. Thus the “1s” and “0s” of digital codes stand for actual physical states of the machine. If the human brain is also a system that functions through instantiating representation than the goal of cognitive science is to uncover the machine language of the brain: to make the connection between the psychological description of the subject and the actual physical state of the nervous system.

The brain does, in fact, possess physical features that lend themselves to a theory of symbolic architecture similar to that found in digital computers. The brain is a massive assemblage of individual neurons that interact with each other through the flow of electrical impulses (“cascades”). The impulses do not pass arbitrarily, of course; the brain shows immense organizational complexity. But essentially one neuron or group of neurons will, upon being “lit up” by a cascade of electricity, either send the event onward to the downstream neurons of fail to do so, and this can be seen as the “1/0” analog. What’s more, between neurons there is a space, the synaptic cleft, which contains a soup of neurotransmitters that buffer the electrical connection (they can be more or less conductive). So instead of an “on/off” potential, like a light switch, there is a gradient potential, like a volume control. This vastly increases the potential number of physical states of which the brain is capable. All of this constitutes a non-arbitrary reason for thinking that the brain may indeed function like a traditional computer: the synaptic pattern could be the symbolic architecture of the brain just as the disposition of the gates in the chips is the symbolic architecture of the computer.

However a new generation of computer models now challenges classical computation and its axiom that representation is necessary for computation. In this new generation of research, computers are actually modeled on brains while at the same time the new computers are contributing to new insights into how brains themselves work. This movement is sometimes referred to as “parallel distributed processing” and as the “neural net model,” but it has come to be popularly known as “connectionism.”

Classical computation has some limiting and apparently intractable problems. As anyone who has worked with computers knows, they are insufferably single-minded. This is natural, as they can only do what they are told to do by their programmers; “garbage in, garbage out.” One of the central problems for traditional computers is the “framing problem.” Consider any homonym, for example “bank.” An ordinary human has no trouble during conversation distinguishing between the two senses in sentences like “I was laying on the bank of the river” versus “I made a withdrawal from my bank.” Traditional computers are strictly limited in terms of contextualizing. This is because computers don’t actually know anything. They are devices for manipulating symbols and nothing more.

What’s more, traditional computers can’t learn anything new. They know what they are told. Now, remember the Rationalist/Empiricist debate. The Rationalists thought that there was an innate conceptual structure, incarnate in language, of essentially mathematical and logical principles, and this structure (the mind, or soul) was the source and basis of rational behavior. The Empiricists argued that a naturalistic psychology required that there be nothing more than an ability to learn from experience on the basis of trial and error, and were skeptical of non-physical states and entities. Connectionist computer models are empiricist approaches to computing in the same way that behaviorism is an empiricist approach to psychology. Connectionist machines do indeed show some primitive ability to learn on their own; they function (ideally) with no recourse to internal codes or representations; and they are solidly based on basic principles of evolutionary biology.

Connectionist machines function, as brains do, by forming patterns of activation. An input layer of nodes are electrically stimulated and this layer accordingly stimulates some number of “hidden,” internal layers which ultimately stimulate the output layer. Activation potentials can be weighted in various ways but the basic mechanism is the number of nodal connections which can constitute a threshold for downstream activation:

(Insert figure of simple connectionism: input layer, hidden layer, output layer)

This technology underlies handwriting-, voice- and facial-recognition functions that are now commonplace (an original application was for submarine sonar submarine-recognition and missile-recognition). This is achieved through trial-and-error. A trainer adjusts the activation potentials to increase correct outputs and to extinguish incorrect ones. This process does not require any internal symbolic content.

Here it is useful to note that Darwin’s model of evolution as outcomes-based selection over random variation is very much a product of empiricism. In fact Darwin was reading the Scottish Enlightenment economist Adam Smith’s 1776 Wealth of Nations, with its account of larger economic structures formed from the bottom up through iterations of economic exchanges between autonomous, self-interested individuals when he was developing his account of natural selection (Darwin 1859). An important distinction between the Rationalist program and the Empiricist one is that Rationalists tend to see complex systems as organized from the top down whereas Empiricists see complexity as emerging from the bottom up. The distinction between classical computation and connectionist computing mirrors this distinction.

However the field of AI is moving in even more radical directions. Although modern cognitive scientists will obviously disavow Cartesian dualism about the mind and the body, in a sense the Cartesian model has often been simply transposed into a brain-body distinction. On a common view it is the brain that is (now) the “cognitive theater,” the seat of representations, the CPU where thinking takes place: the same role Descartes assigned to the res cogitans (Hacker). This view underlies the assumption that AI research is simply an extension of computer science. That collective assumption is now collapsing.

IV. Robotics

On a representational model, “beliefs” and other mental states are instantiated in the form of mental content: language, images and so forth “in the head.” As I said, this is recognizably a continuation of a kind of Cartesian dualism. Indeed representational models are essentially dualistic if representations are taken to have semantic properties that are not analyzable as physical properties (this is one of a number of philosophical issues that I went into to some depth in the class). An alternative view is that psychological predicates are predicated not of brains but of whole persons.

Stomachs don’t eat lunch. People eat lunch. True enough that one needs a stomach to eat one’s lunch, but it doesn’t explain how a person eats lunch to say, “Their stomach eats lunch for them.” Brains don’t think. They don’t imagine, dream, solve problems or recognize patterns. People do those things, just as people believe, desire, hope, fear, etc. In fact, committing this mereological fallacy – the fallacy of confusing the part with the whole – obstructed our ability to learn what it is that brains actually do. We were sidetracked by the misconception that brains are little people in our heads.

“Embodied cognition” is the name given to a recent movement in cognitive science that rejects representational models of thought. The idea is that “thinking” is an activity that is distributed over the whole body. This movement has been in a particularly fertile dialectical relationship with robotics. (Not surprisingly this community has developed some excellent internet resources where students can see footage of robots in action.) It is clear enough that the future of AI lies as much with the field of robotics as with the field of computer science. What is important in an interdisciplinary context is to see the underlying, and quite old, philosophical considerations that make that clear. This also presents an opportunity to discuss the history and philosophy of science.

A little bit of naturalist apologia

2011-05-29T12:29:00.000-04:00

We live in a world where most natural phenomena, from the micro level of atoms, cells and molecules up to the macro level of galaxies and the universe itself, seem to be describable and explicable in physical terms. Physicalism (I mean by this term the metaphysical position that only the physical universe exists) is, as I said, by no means triumphant (and it is a reasonable point that contemporary physics itself presents us with a still-mysterious and newly-strange picture of the universe). There are ongoing popular metaphysical arguments about evolutionary biology and about cosmology, for example. But it is a striking fact about contemporary culture that psychology (and by extension the behavioral and social disciplines) are still not considered to be integrated into our otherwise generally physicalist metaphysics. Put another way, while many people today have firmly internalized physicalist intuitions about organic life, say, or about distant celestial objects, physicalist theories of mind still meet with resistance today, even among secular people who have broadly physicalist attitudes.

I’m not someone motivated mostly by ideology. I’ve always been impressed by Socrates’ description (in the Theatetus) of the search for knowledge as the activity of becoming aware of what it is that one truly believes, and then stating that belief, above all to oneself, as clearly and courageously as possible (in fact Socrates is claiming, contra his relativist antagonists, that this is the essential, unavoidable human activity). I’ve had the salutary experience of changing my mind and reversing myself several times during my relationship with philosophy of mind. Now I just want to develop the soundest view of the matter that I can, as one climbs a mountain. One of the worst faults a philosopher can have is the tendency to magical thinking: trying to make a brief for what one wants to be true.

However another couple of paragraphs of self-explanation are warranted. I know this because I have spent the past ten years or so teaching the philosophy of mind to undergraduates at two large state universities. Inevitably this involves, among other things, leading a lay audience to discuss, usually for the first time, the topic of naturalism with regard to human nature and to the mind. Of course there are people who arrive in the classroom already thoroughly naturalistic. But consistently there are people who struggle with this topic for deeper, cultural reasons. Although this discussion is rarely included in books on philosophy of mind, I have found that it is best to present some apologia at the beginning for students who may have some preconceptions that can turn them off, as well as to reassure them that I too think that these are legitimate concerns that can be discussed if they wish.

OK, so here’s an ideological argument: Humans are depressingly alienated from nature. Our relationship with the rest of the biota on this planet is not a good one. Urgent action is necessary to stem climate change, species extinction and other environmental problems that pose grave threats. However we also need longer-term cultural evolution, a change in our attitude towards our relationship with nature, and this change is effected to some extent by cultural workers such as artists, philosophers and writers.

It is my opinion that human exceptionalism, and a lot of bad metaphysics down a lot of centuries that came with it, is one root of our dysfunctional relationship with nature. I think that naturalism about psychology is the most progressive view. I think that naturalism is also the most spiritual view. And it is the healthiest view of human nature. I may be all wrong on all of that. But the reader ought to understand that I concede no quarter of the argument between physicalism about the mind and its alternatives, including discussions in terms of enlightenment, ethics, freedom, spirituality and so forth. Those discussions, however, will form little or no part of this book.

A programmatic point that will be discussed, though, is the importance of clearing up some of the logical and linguistic problems that we continue to have with our concept of “mind” in order to make progress in experimental science. Theory can have a good deal to say about the development of experimental protocols, and good theory will make these implications clear.

Metaphysics and the philosophy of mind

2011-05-22T13:00:00.002-04:00

This is a book about the metaphysics of the mind/body problem. Metaphysics (or “ontology”) is the study of what exists (Aristotle called it the study of “being”). To many people today metaphysics seems anachronistic. Haven’t we settled the issue of what exists, they might ask, in favor of the physical universe? And isn’t natural science the way we produce knowledge about this universe? How could more work in metaphysics possibly generate any persuasive arguments, if “metaphysics” is not simply “physics”? Arguments about the relationship between the mind and the body that aren’t grounded in empirical research of some sort can’t hope to be legitimate in a world awash in data from experimental psychology, neuroscience, computer science, evolutionary biology, linguistics and the myriad of interdisciplinary areas of research that today we call “cognitive studies.” Isn’t a metaphysician a mere poet of speculation? Diverting at best, but such a person has no hope of producing useful knowledge. That, anyway, is often the initial reaction one meets with the topic of the metaphysics of the mind/body problem. I will respond to this initial “meta”-challenge in two ways.

First, I completely embrace the spirit, and much of the letter, of this initial objection. I too take it as axiomatic that what exists is the physical universe (by “physical” I mean the universe of matter and energy, or maybe matter/energy; I don’t pretend to be sophisticated about theoretical physics). I don’t think that humans are composed of physical bodies and non-physical souls, like a traditional mind/body dualist. I think that humans are physical through and through, animals that evolved here on earth through a long process of evolution the contingencies of which were, and continue to be, bounded by the constants of biology, chemistry, and physics. I don’t expect to discover that humans are angels, or that the physical universe is an illusion and humans are non-physical spirits, or anything like that.

The universe is as magical, mysterious and mystical as it may be; I don’t know anything about the ultimate composition or nature of the universe. I have no interest in making a brief for reduction, as if natural science can address every one of our wonders, or even potentially could. I don’t even know what we’re talking about when we use that kind of language. My claim is much humbler: whatever nature in general is like, humans are like that. Humans are not miracles, if a “miracle” is defined as an exception to the laws of nature. Call me an “anti-humanist.” I hold the anti-humanist view simply because I know of no reason to think that humans are miracles; I stress it because a deeply internalized assumption of human exceptionalism continues to be a barrier to progress across the whole range of the behavioral and cognitive sciences.

Which brings me to the second response to the objection that metaphysics is anachronistic: it is certainly not true that the contemporary society of educated people embraces anti-humanism as I just defined it. A great many college students, most people walking down the street and the overwhelming majority of the world’s population today continue to think that the mind is something distinct from the body or, at least, that mental phenomena cannot be adequately described and explained in wholly physical terms. This conviction has various sources that range from traditional, usually religion-based beliefs about souls, afterlives and so forth to more modern notions, such as the view that a naturalistic view of human nature is perniciously reductive and to be resisted by the liberal-minded, or perhaps that science itself is nothing more than a socially-constructed “conceptual scheme” with no particular claim to legitimacy, and so on. For another thing, very sophisticated versions of human exceptionalism exist in the academy today (for example among some linguists), such that it is by no means established conventional wisdom that physical science subsumes psychology by metaphysical axiom.

Metaphysics is not something that is replaced by physics. Physicalism is a particular metaphysical position. Everyone has metaphysical assumptions, articulated or not, whether they want to or not, and they always will. The person who chafes at the idea that there is still a need for explicitly metaphysical discussion is claiming that our shared metaphysical assumptions are currently stable, not that “there is no such thing as metaphysics,” although they may unreflectively put it that way. It’s true that physicalism is currently the ruling metaphysical paradigm among cognitive scientists, psychologists, philosophers and so on, and I too labor within this paradigm, albeit with some important qualifications that are discussed in the second part of Chapter Two.

Elan Mental

2011-05-15T10:36:00.000-04:00

The claim that there is something (the quality of phenomenal experience) that cannot be explained by physical science is strictly analogous to the 19th century “vitalist” claim that the property of being alive could not be explained by physical science (the phrase “élan vital” was actually coined later, in 1907, by Henri Bergson in his book Creative Evolution). Consider all of the physical facts about physical states and processes in the body, the vitalist argued: singularly or together none of these facts entail that the body be alive.

This “hard problem” was never “solved.” It simply faded away as organic chemistry and physiology steadily explicated the physical mechanisms and processes occurring in various parts of cells, and in the various organs of the body. This took some time, well into the 20th century, but by the 1940s, anyway, it was no longer credible to claim that “life” was something that might not be present when these mechanisms and processes of organic chemistry were present, or might be present in their absence. “Life” will always be an ambiguous concept to some extent (there is ongoing debate as to whether viruses are living, for example), because it is an emergent property, but its physical nature is no longer seriously challenged. The concept of “consciousness” is now undergoing the same evolutionary process – not a similar process, the very same process.

This analogy has been prominently rehearsed by Patricia Churchland and by John Searle, among others. I will consider Searle’s version a little more closely by way of setting up the last chapter, where I will discuss the relationship between intentionality and consciousness. Searle makes an analogy between the solidity of a table and the consciousness of a brain: the table’s solidity is a macro-property that emerges from the micro-properties of the wood molecules (which are lattice-like). Consciousness, he suggests, is a macro-property that emerges from the micro-properties of neurons (although he doesn’t claim to know which micro-properties or why).

There are two problems with Searle’s analogy. First, in the case of the wood molecule and the table, they share the same property in the first place: the lattice-like structure of the wood molecule, like a folded piece of paper, just is solid (can bear weight by virtue of its structure). So solidity is not an “emergent macro-property,” solidity is already a property of the “micro” ingredients. If the question is “How can physical objects support weight?” then appeal to the weight-bearing nature of the wood molecule only pushes this question back a step. This problem with the analogy is irremediable: if the argument is that brains are conscious because neurons are conscious we have once again committed the hard-to-avoid error of including something mental in our purported recipe for the mental. If not, then the analogy does not go through: the wood molecules and the table share a property in common, so we do not have an actual example of a macro-property emerging from a micro-property (that is not to say that we couldn’t find such an example, only that this one isn’t it).

The second problem is more serious and to the point of the present discussion. Psychological predicates, as I argued at length in Chapter Two, are not predicated of brains or nervous systems but of whole persons. This goes for consciousness every bit as much as it does for intentionality. Brains no more feel or sense things than they think about or imagine things. Persons think and feel. Asserting this does not exclude me from the club of materialists in any way.

The crucial difference between intentionality and consciousness is that while intentional states are supervenient and therefore unexplainable through reductive materialism, phenomenal states are not supervenient and so a legitimate answer to the question “Why does it feel like that?” is “Because it is that specific physical body interacting with that specific physical feature of the environment (chocolate molecule, blue-reflecting surface, soft pillow etc)” – strict reductive materialism. We can say this, I think, even if we accept the argument that the question “Why does it feel like that?” is itself in a sense illegitimate since there is no way to fill in the sense of “that,” as Hume, Wittgenstein and the Buddhists argue. The basic insight is that having these conscious experiences is indistinguishable from having this physical body in this physical world.

There is only one sense in which we can coherently say that our own phenomenal experiences are in any way similar to those of other conscious beings, such that we can grasp a link between intentionality (universal among all intelligent beings) and consciousness (unique to each conscious being). In this book I have emphasized the distinction between intentionality and consciousness. The last chapter will explore the connection between them.

Hyper-chauvinistic type-to-type reductive materialism

2011-05-08T18:36:00.000-04:00

OK, it’s not really hyper-chauvinistic type-to-type reductive materialism, because there isn’t anything to “reduce,” if the above arguments are persuasive. But the fact is that so far as qualitative experience is concerned, yours is what it is because you have the body that you have. “Experiencing” is just identical to living in a body like that.

A crucial difference between intentional states and phenomenal states is that phenomenal states are not picked out operationally, while intentional states are, even though the criteria for use of phenomenal predicates is operational just as they are for the use of intentional predicates. This is because phenomenal experience is outside of the reach of language altogether: precisely because it is unique to oneself and thus incommunicable to another. This is a difference between bodies.

Saul Kripke, much of whose work was inspired by Wittgenstein, argued that reduction was impossible on linguistic grounds. A phenomenal word like “pain” could never be defined as, say, “C-fibers firing” because the word “pain” referred to the feeling of pain (that phenomenal experience), and, Kripke argued, one can imagine being in pain without one’s C-fibers firing (or without having C-fibers at all) and that one’s C-fibers might be firing (or what have you) without one feeling pain. Of course Kripke’s point is about all phenomenal language but, as we have seen, there is no coherent way to separate “experience of the world” from “the world.”

Kripke’s claim amounts to saying that one can imagine experiencing this world without this world (which includes one’s body), or that this world (including this body) could exist without these experiences. I take Hume’s point that these sorts of claims about what can be conceived or imagined are meaningless, because phenomenal experience of the world and the world itself cannot be metaphysically distinguished from each other.

However this does not mean that “pain” might be defined as C-fibers firing: it could not. Use of the word “pain” will be determined operationally (as David Lewis insisted) as the use of all words is determined operationally. Constructions such as “pain-for-me” have no functional role in communication, but one’s (actual) pain can be mentioned even if there is no use for a term that designates it: it is no less real for being inexpressible. Meanwhile Kripke is not entitled to the claim that one’s body (one’s C-fibers firing) is causing one to have a sensation of pain that is distinct from its cause. Such a claim is irremediably dualist: one’s body is not the cause of one’s phenomenal experience. One just is one’s C-fibers firing etc.

Better, then, to drop the “reductive.” But “type-to-type” is also a dubious phrase. Unlike in the case of intentional states, there is no distinction between types and tokens when we are referring to conscious experience: each body is to some extent unique, and consciousness (unlike intentionality) is not supervenient. And the suffix “hyper” is perhaps a bit of rhetoric on my part. Better, perhaps, to call our theory of phenomenal mind simply “chauvinistic materialism,” if the need is still felt for a “theory” to account for a pseudoproblem.

This is no problem for science; since science, understood as a cultural artifact, is limited to the intersubjective, and phenomenal experience is wholly subjective (that’s why it’s a little silly to say that we have a “theory” here at all). Thus we can contemplate the resolution of the so-called “hard” problem of consciousness.

Phenomenal states are not supervenient

2011-05-01T13:09:00.000-04:00

Intentional states are multiply realizable, and functionalism was motivated by this fact. The supervenient nature of intentional states constitutes a real block to reductive materialism for intentionality. However intentional states can be individuated operationally. The intuition that the psychological description “He likes chocolate” involves a reference to the subject’s qualitative experience of tasting chocolate is wrong (or, we can mention the qualitative experience but we cannot actually convey it). In the case of the Martians we might not know if they even “taste” things at all; nonetheless we might come to know that they like chocolate.

A consequence of the necessarily operational basis of intentional descriptions is that, to use an example made famous by Daniel Dennett (although I don’t know that Dennett would agree with my line here), a lowly thermostat is a kind of intentional system: we can determine when it thinks that the room is too cold, just right or too hot. The intuition that this can’t be, that a thermostat is clearly not a mind, is a consequence of internalizing the traditional homogeneous concept of “mind” (because the thermostat has no Nagelian experience), aggravated by the prevailing dogma that thinking necessarily involves representations. When we disambiguate “mind” and see that intentionality is something altogether different than consciousness there is no denying that the thermostat is, in fact, an intentional being; nor does that fact in any way compromise our philosophical use of the term “intentionality.”

The qualities of experience, on the other hand, are not supervenient. It is plainly true that humans, dolphins, probable intelligent extraterrestrials and possible intelligent artifacts, among an indefinitely large set of other beings, can all believe that the chocolate is in the box, desire the chocolate and so forth. But there is no reason whatever to think that chocolate tastes like that (the way it tastes to me, say) for all of the members of the set: there isn’t even any reason to think that all of the members of the set of chocolate-desirers taste anything at all.

Ironically what this amounts to is that intentional properties are more ontologically mysterious, not less, than phenomenal properties. Consciousness has been called the “hard problem,” but in fact the right metaphysical account of consciousness is, relative to that of intentionality, positively straightforward.

Troubles with the zombie argument in philosophy of mind

2011-04-24T13:17:00.001-04:00

First of all it is important to keep in mind my initial disambiguation of intentional states and phenomenal states. It is already established that intentional states, since they are supervenient on physical states, can only be categorized operationally. Phenomenal states, as the friend of qualia has characterized them, cannot be categorized operationally (since they are beyond the reach of language). Of course an android could distinguish color surfaces without recourse to qualitative experience. We don’t think that there is “something that it’s like” for welder-directing robots in automobile factories to locate the seams with lasers. So when we are told that we can conceive of zombies it must be that we are meant to be conceiving of beings that are physically identical to humans but have no conscious experience. That functional descriptions can supervene on multiple physical descriptions has no bearing on the ontological status of qualia at all. I will make two arguments that are variations on the larger set of arguments presented here. First that the zombie counterfactual assumes something that it purports to show, and second that the zombie argument is an example of skepticism and is vulnerable to some counter-skeptical arguments.

The zombie counterfactual turns out to be question-begging: the friend of qualia has included qualia-body dualism as one of the premises. The claim is that we can conceive of beings that are physically identical to humans but that do not have immaterial phenomenal mental properties, unlike, presumably, the actual humans. To see this, try the same thought experiment only with the initial assumption (the most reasonable one, on the principle of parsimony) that qualitative experience will ultimately be explicable in wholly physical terms (that is, assume materialism as the default metaphysical position). The thought experiment now looks strikingly different.

Now (assuming materialism to be axiomatic, instead of dualism) the zombie argument is not question-begging: our initial assumption is that both the “blueness” of the surface of the plastic chair and the “blueness” of the phenomenal experience of the surface of the plastic chair are qualities had by virtue of the physical properties of the perceived chair and the perceiving body respectively. Now try this assertion on for size: “I can conceive of the plastic chair as having the identical physical properties that it now has (including its light-absorbing and –reflecting properties) but not having any color at all.” This is definitely inconceivable. When I try to conceive of an object with no color I for one try to imagine that the objects are transparent - I’m not sure if that counts as an object that has no color but it’s the best I can do. I cannot conceive of a physical object that is physically identical to an object that is colored but that has no color. This is just an application of the argument that to the extent that what I know, I know through “experience,” it makes no sense to draw a distinction between the phenomenal and the physical.

A second line of argument is suggested by the way Wittgenstein’s linguistic arguments can be deployed against skepticism. “Philosophical skepticism” is any argument to the effect that you don’t know something that you’re certain that you do know. Modern skepticism is closely connected to rationalism: Descartes thought that logical proof was the paradigm of “knowledge,” and it turned out, perhaps unsurprisingly, that by that standard we know very little. “The Problem of Other Minds” is a skeptical argument: you’re certain that other people have experiences and thoughts like yours but it seems that you can’t prove it. The Zombie problem is a variant on the problem of other minds: can’t you just see that other people are conscious? What would it be to doubt this? If the Zombie argument is an example of skepticism then we should be able to extend Wittgenstein’s treatment of skepticism to the Zombie argument.

A famous back-and-forth between Wittgenstein and G. E. Moore is good for illuminating this. In his essay “Proof of an External World” (1939) and elsewhere Moore is arguing in much the same philosophical spirit as Wittgenstein (they both think that skepticism is a pseudo-problem with roots in a faulty understanding of language), but Wittgenstein’s remarks on Moore’s arguments (included in On Certainty) make a crucial difference clear. Moore, presaging the “Ordinary Language” movement, wanted to show that “common sense,” by which he meant, roughly, ordinary talking and thinking about our physical selves in our physical world, was better defended with reasons than the speculative bases of skepticism and the “idealism” (really a kind of phenomenalism) still powerful in English philosophy at the beginning of the 20th century. Moore thought that our perceptions of our own bodies in the environment were instances – paradigmatic instances - of knowledge, not belief. Holding up his hand he would say, “I know I have a hand.” From the plain fact that I know I have a hand there arises similar knowledge of, ultimately, the external world: the keyboard is a reason for (believing in) the hand, the hand is a reason for the keyboard; the desk is a reason for them both and so on.

Wittgenstein’s response to skepticism is altogether different. Drawing on his premise that language must have operational criteria for determining appropriate conditions of use, Wittgenstein challenges the skeptic’s use of the verb “to know.” Take an ordinary (non-philosophical) instance of using that verb: “Do you know where your keys are?” The question makes sense because one might know or might not know, and “knowing” can be defined operationally: one can put one’s hands on one’s keys or one cannot. The question, “Do you know that the external world exists?” has no criterion for use: nothing could count as demonstrating that the external world either does or does not exist. That is, we neither “know” nor do we “not know” that the external world exists. The word “knowledge” has no place here. Where Moore proposed a kind of normative epistemology that would, if accepted, constitute an argument for the existence of the external world, Wittgenstein denies that there could be any argument one way or the other: Moore has taken the bait and tried to play a game that can’t be played.

Here we can see Wittgenstein’s “soft” arguments about language and his “hard” argument called “solipsism” come together. It is important also to see that Wittgenstein is much closer to Hume than Moore is. Hume (like Berkeley) stresses that the assertion that the external world “exists” is just as untenable as the assertion that it might not. Both sides of the disjunction are nonsense, if either side is.

The problem of other minds is exposed to the same treatment as a pseudo-problem. PI 246:

In what sense are my sensations private? – Well, only I can know whether I am really in pain; another person can only surmise it. – In one way this is wrong, and in another nonsense. If we are using the word “to know” as it is normally used (and how else are we to use it?), then other people very often know when I am in pain. – Yes, but all the same not with the certainty with which I know it myself! – It can’t be said of me at all (except perhaps as a joke) that I know I am in pain. What is it supposed to mean – except perhaps that I am in pain?
Other people cannot be said to learn of my sensations only from my behavior, - for I cannot be said to learn of them. I have them.
The truth is: it makes sense to say about other people that they doubt whether I am in pain; but not to say it about myself.

If I say “I know he’s conscious” and you challenge me by excluding all operational criteria from counting as justification for my claim, all you will do is change the ordinary meaning of the (public) word “conscious.” But then I’ll just have to start using another word for the same purpose, because what I have to say will remain exactly the same. PI 403:

If I were to reserve the word “pain” solely for what I had hitherto called “my pain”, and others “L. W.’s pain”, I should do other people no injustice, so long as a notation were provided in which the loss of the word “pain” in other connexions were somehow supplied. Other people would still be pitied, treated by doctors and so on. It would, of course, be no objection to this mode of expression to say: “But look here, other people have just the same as you!”
But what should I gain from this new kind of account? Nothing. But after all neither does the solipsist want any practical advantage when he advances his view!

As for “consciousness,” its meaning will now be anything you care to stipulate – in other words nothing - since you’ve stipulated that one can’t hear, see, smell, taste or touch anything that could even possibly indicate its presence: much like the word “god.” Thinking about the semantics of the word “god” brings us back to the first argument about the question-begging nature of the Zombie counterfactual. If the claim is that an operational theory of mind such as functionalism, specifically, has a problem with qualia, it must at least be a tacit assumption that there could be some non-operational theory of mind (a traditional one? a popular one? a philosophical one?) that does not: one that actually incorporates information about “what it’s like” into psychological descriptions and explanations. But there is no theory of mind like that, and if the arguments rehearsed in this chapter are correct there cannot be one.

Even after all of this, though, Nagel’s point still stands: there is “something that it’s like” for me to have a qualitative experience, and mine might very well be different from a Martian’s, or a dog’s or even yours. Although language cannot express these “qualia,” much less produce coherent claims that they are “properties” distinct from physical properties, our progress here has not been wholly destructive. I am now in a position to say a few things, after all, about the metaphysics of phenomenal experience.

Turning the Inverted Spectrum on its Head

2011-04-17T12:48:00.000-04:00

The inverted spectrum argument is first found (remarkably full-blown) in Locke’s Essay Concerning Human Understanding (II, xxxii,15, “Of True and False Ideas”):

"Neither would it carry any Imputation of Falshood to our simple Ideas, if by the different Structure of our Organs, it were so ordered, That the same Object should produce in several Men's Minds different Ideas at the same time; v.g. if the Idea, that a Violet produced in one Man's Mind by his Eyes, were the same that a Marigold produces in another Man's, and vice versâ. For since this could never be known: because one Man's Mind could not pass into another Man's Body, to perceive, what Appearances were produced by those Organs; neither the Ideas hereby, nor the Names, would be at all confounded, or any Falshood be in either. For all Things, that had the Texture of a Violet, producing constantly the Idea, which he called Blue, and those that had the Texture of a Marigold, producing constantly the Idea, which he as constantly called Yellow, whatever those Appearances were in his Mind; he would be able as regularly to distinguish Things for his Use by those Appearances, and understand, and signify those distinctions, marked by the Names Blue and Yellow, as if the Appearances, or Ideas in his Mind, received from those two Flowers, were exactly the same, with the Ideas in other Men's Minds."

Locke composed this counterfactual as part of his effort to show that “tertiary” properties (the properties of mental “ideas”) were different from secondary (the causal properties of the object of perception to cause ideas) and primary (the physical properties of the objects themselves). This was the property dualism repudiated by Berkeley and Hume. In the 20th century the inverted spectrum has had a strong career as a demonstration of the failure of functionalism to handle qualitative properties and, more to the point, as a supposed demonstration that there are such properties (in substance this is very much the same as Locke’s original application).

Imagine someone whose color spectrum was inverted (the “invert”): where normal people saw red, the invert saw blue, where blue, red. Such a person, raised among normal, English-speaking people, would be functionally indistinguishable from anyone else: asked to go out to the car and get the blue bag, say, they would perform this task exactly as anyone else would. Neither they nor anyone else would have any way of knowing that the invert’s experience of seeing the blue surface of the bag was the same experience that everyone else had when they saw a red surface, since the invert, like everyone else, would refer to such a surface as "blue." Since the invert would be functionally identical to a normal person, a functionalist is committed to the position that there is nothing different about their mental state. But (the argument goes) of course there is something different about their mental state: the quale, or phenomenal quality of the experience, is different. Thus functionalism is false.

Wittgenstein argues that the absent qualia argument demonstrates just the opposite of what the friend of qualia claims: since it is not even in principle possible for public language (the only kind of language there is) to pick out private sensations, phenomenal properties are not a problem for operationalist approaches. No theory of mind (or science of mind or description of mind) will ever include any actual discussion of the specific quality of any specific private sensations, because they cannot be discussed. As for the alleged discussion of phenomenal experience we find in philosophy, this is an instance of confusing mention with use - just as one can mention “all sentences that have never been expressed,” but cannot cite one. Outside of (misguided) philosophical conversation there is no context for use of indexically subjective language such as “blue-for-me” as opposed to the intersubjective “blue” which, like all words, necessarily has public criteria for appropriate contexts of use. This is why even the very best of the phenomenologists (Husserl, Merleau-Ponty) never seem to get beyond a sort of “Prolegomena to Some Future Actual Practice of Phenomenology”: after the manifesto there is nothing more that can be said.

So far this is a version of what I am calling the soft argument: the argument is about language, not about the ontological furniture of the world. It has conclusions that perhaps all non-philosophers would find definitive. Qualia do not constitute any sort of obstacle to the naturalization of psychology from the point of view of the scientist because science never could be expected to go beyond the limits imposed on language by its public nature in the first place. Nor is there anything inadequate about our ordinary, colloquial speech about qualitative experience (about, that is, the flavor of the sauce or the hue of the sunset), notwithstanding our individuality, for the same reason. But what about that ontological furniture?

The metaphysical argument will be about the identification of consciousness with experience. The Kantian will say (confining ourselves to the terms of the present discussion) that consciousness is a necessary precondition for the possibility of experience, hence not identical to it. This argument might gain some traction if we concede to the Kantian the point that “experiencing” an object entails bringing the object under a concept (although see the discussion of Kant in Chapter Two), but that very distinction between sensation and perception in the case of objects itself entails that sensation (phenomenal experience) is something prior to the formation of a Kantian “representation.” (If the reader is thinking of Aristotle’s nous at this point I beg your indulgence until Chapter Four.)

I have been using the word “consciousness” as synonymous with phenomenal experience, but the word is also sometimes used in regard to intentional states. Used in its intentional sense, to be “conscious” of an object is, on the traditional view, to form a representation of it or, on the view that I advocate, to be in some sort of relationship to it. But it is incoherent to say that to be conscious of pain, say, is to form a representation of pain or to be in a relationship to pain. In its phenomenal sense the word “consciousness” just refers to the sum of phenomenal experience: pain is a constituent of consciousness, not one of its objects. I may be intentionally conscious of pain at some higher level of psychological organization (one that can be picked out with operational criteria), but it makes no sense to say that I have to form a representation of pain or be in a relationship to pain to have an experience of pain.

The same is true for color qualia or for any qualitative experience. Kripke famously pointed out that the word “pain” just refers to the sensation of pain. “Blue,” in its phenomenal sense, just refers to the sensation of blue. It is one of the components of experience, not some object of experience. Experience is qualia; qualia are experience. So (to get back to the supposed metaphysical implications of the inverted spectrum) it makes no sense to say that experience has properties. Only the objects of experience have properties.

Where this leaves us is at the point of distinction between Frank Jackson’s “What Mary Didn’t Know” essay and Thomas Nagel’s equally famous essay “What is it Like to Be a Bat?” In that article Nagel makes an argument very close to but not identical to Jackson’s. No matter how much we come to know (physiologically) about the echolocation organ of the bat, Nagel argues, we will never know “what it is like” to experience the world in the way the bat does. The difference between Nagel and Jackson is that, granting the present argument that (qualitative) experience itself has no properties, experience itself does not constitute any sort of information (experience is rather the ground of information). We can concede that different conscious beings have different experiences without conceding that this entails any ontological implications.

Some writers have argued that the invert cannot, in fact, be conceived (Douglas Hofstadter holds this view, for example). I do not take that position. Since I do not see how to refute the Wittgenstein/Buddhism non-duality version of “solipsism,” I have no motive to try to prove that we do, in fact, grasp the qualitative nature of the experiences of others. Even if we could do so we could not express this “grasp” linguistically. However there is a different application of the “absent qualia” argument, one that holds that we can conceive of beings functionally (“behaviorally” is a more appropriate word here) equivalent to humans that have no qualitative experiences: “zombies.” David Chalmers’ entire argument for qualia-matter dualism hangs on this claim. I do not believe that we can “conceive” of any such thing.

Buddhism and Qualia

2011-04-03T13:03:00.000-04:00

“Buddhism” is the name of an ancient tradition (with roots in the older Hindu tradition) that includes both philosophical and spiritual ideas and practices. After 2,500 years it is no surprise to find that classical Indian and Chinese philosophy, including Hindu and Buddhist philosophy, encompass a gamut of positions at least as diverse as those found in the European philosophical tradition. There are, in the philosophical senses of the terms, materialist Buddhists and idealist Buddhists, foundationalist Buddhists and relativist Buddhists. By titling this section “Buddhism” I do not mean to suggest that the arguments discussed here are characteristic of all of Buddhist thought. However these particular arguments do constitute a persistent and venerable thread and I will discuss several different sources. These arguments have roots in some of the most basic elements of Buddhist teaching. While I have chosen to concentrate on the Mahayana tradition that is not meant to suggest that other traditions and schools may not include similar arguments.

There is a complex mix of philosophical, psychological, spiritual and social motivations informing the life of Siddhartha Guatama and his ultimate focus on the nature of the self. The severe caste structure of Indian Hindu society was tightly tied to traditional Hindu concepts of karma and reincarnation. Souls rose and fell over the course of thousands of lifetimes, and humans were low on the scale of karmic life: overall the effect was fatalistic and conservative. At the same time the sixth century BC in India was a period of transformation when a vernacular Sanskrit brought cultural upheavals that included the beginnings of the Epic Hindu literature and the flowering of diverse Hindu sects, Jainism and other movements besides Buddhism.

The basic Buddha Dharma is the most well-known piece of Buddhist philosophy. These are the “Four Noble Truths”: All life is suffering (“duhkha”), says the Buddha; we suffer because we are caught in a cycle of sensual satisfaction and craving; this suffering can be alleviated and even brought to an end altogether; and the “Eightfold Path” of right attitudes and practices will lead to the cessation of suffering. From this starting point Buddhism developed, among other things, a philosophical tradition with a sustained interest in the nature of consciousness, experience and the relationship between the self and the world. The idea that the “ego”-self, the self that arises through the cycle of duhkha, is the encumbrance that the “bodhisattva,” or enlightened self, needs to lose in order to achieve nirvana is prominent in the earliest teachings attributed to Siddhartha.

It is a somewhat dangerous business bringing a discussion of Buddhism into a book focused on contemporary philosophy of mind. I want to stick closely to the line of argument that has brought us to this relatively exotic territory. The overall claim is that the metaphysical problem of the alleged existence of phenomenal properties as distinct from physical properties is a pseudoproblem. I have presented arguments of Hume and Wittgenstein that I think are persuasive versions of this claim. In the case of Wittgenstein I argue that the “solipsism” argument common to the early and late works entails that phenomenal properties do not exist (are not part of this world). The view that the self is “emptiness,” and that the overcoming of the duality between the self and the world constitutes nirvana (enlightenment) is extremely similar, if not identical, to Wittgenstein’s solipsism argument. I will describe the Mahayana version of the argument and then present some textual evidence for my interpretation from classical sources.

The earlier Abhidharma School taught that “dharmas” were individual, autonomous atoms of experience; something akin to Leibniz’s infinity of monads. This is idealist ontology: primary being was dharma which was understood as consciousness (more or less: the bulk of Abhidharma metaphysics consists of discussions of just what “dharma” is after all). Although the arising ego-self, on this view, dissolves into infinitude of discrete dharmas, these dharmas are constitutive of the world. Mahayana Buddhism attempted to go further and collapse the duality between the mental and the non-mental: a kind of ultimate erasure of the self from the world that resulted in freedom from the bonds of the karmic cycle, the traditional goal of both Hinduism and Buddhism. Their formula was

MIND = EXPERIENCE = WORLD

One must resist the Cartesian instinct to interpret this formula as stating that the world collapses into the mind (as it does on the idealist view). The idea is that each consciousness is a universe. That universe at the middle of which you are sitting is you: it/you came into existence when it/you became conscious. When you pass away the universe you inhabit will pass away: for that universe is you. This is a line that could be defended by Hume: he might point out, for example, that if all any talk about “the world” could possibly be referring to is experience, then it makes no sense to refer to “a world” beyond experience, and thus it is incoherent to speak of a common world for all of the “microcosms” – a pseudoproblem.

An account of nirvana as the realization of the non-duality of mind and world can be found in Mahayana Buddhism and its descendents. The Prajna-paramita, or Wisdom Sutra, was traditionally taken to be the word of the Buddha, but scholars trace its origins to the first century AD and it appears that it was composed over the next several centuries. In a chapter titled “Mara” (a malevolent deity who lays traps for spiritual seekers), we find:

Subhuti: Is it then possible to write down the perfection of wisdom?
The Lord: No, Subhuti. And why? Because the own-being of the perfection of wisdom does not exist, nor that of the other perfections, the emptinesses, the Buddhadharmas or all-knowledge. That of which the own-being does not exist, that is nonexistence; what is nonexistence cannot be written down by the nonexistent.

The spiritual goal here is to free the self from the cycle of satisfaction and craving, and that is accomplished by showing that the self is not part of the world (I am not claiming that our present question about phenomenal properties is what Mahayana Buddhism is all about!). The Wisdom Sutra emphasizes the nonexistence of “own-being,” the being of oneself in one’s world. I chose this passage because the topic is language, and the message conforms to Wittgenstein’s treatment of the alleged problem that arises when we think of phenomenal language, say the word “blue,” as referring to something internal (mental) versus external (physical). Here the predicate “exists” is understood as meaning “exists in this world,” the world of experience: but the experiencing subject is not in this world. This also conforms to Hume’s argument that it makes as little sense to speak of the physical as distinct from the mental as it does to speak of the mental as distinct from the physical. Both sides of the distinction drop away simultaneously.

In the chapter titled “The Exposition of the Nonexistence of Own-Being” the point is more explicit that karma (one’s involvement with duhkha, the cycle of satisfaction and craving) is based on “own-being” and “own-marks,” worldly characteristics of persons. “Dharma” means something in the area of “consciousness,” “self” or “view.”

Subhuti: If, however, these dharmas are empty of own-marks, how can with regard to dharmas which are empty of own-marks a difference or distinction be apprehended (to the effect that one says) “this one is a being of the hells, this one an animal,…this one a god, this one a human….” And as these persons cannot be apprehended, so likewise their karma or its karma result.
The Lord: So it is, Subhuti, so it is, as you say. In respect of dharmas which are empty of own-marks no karma or karma result can be apprehended....But when those too ignorant to cognize dharmas as empty of own-marks manufacture a karma…then, through badly done karma they are hurled into the three states of woe, through what is well done they are reborn among gods and men….Here the Bodhisattva, who courses in perfect wisdom, does not see those dharmas in such a way that, when seeing them, he apprehends any dharma whatever. Not apprehending them he sees that “all dharmas are empty.”

Hundreds of years later and thousands of miles away Eihei Dogen (1200-1253), the classic avatar of Japanese Zen Buddhism, had refined the teaching of the non-duality of mind and world into a meditation practice (“zazen”) and a literary genre (“koan”) that were more minimalist and practice-oriented than the ritual-encrusted, syncretic and generally more baroque Sanskrit and Tibetan traditions, although like Tibetan Tantric Buddhism, Zen and Chinese/Japanese Buddhism in general are descendants of the Mahayana tradition. In his Shobogenzo (“Treasury of the True Dharma Eye”) the solipsistic view has crystallized considerably. Here are quotations from the section “Actualizing the Fundamental Point” (written around 1230):

As all things are buddha-dharma, there is delusion and realization, practice, and birth and death, and there are buddhas and sentient beings.

As the myriad things are without an abiding self, there is no delusion, no realization, no buddha, no sentient being, no birth and death.

The buddha way is, basically, leaping clear of the many and the one.

To carry yourself forward and experience myriad things is delusion. That myriad things come forth and experience themselves is awakening.

When you see forms or hear sounds fully engaging body-and-mind, you grasp things directly.

To study the buddha way is to study the self. To study the self is to forget the self. To forget the self is to be actualized by myriad things, your body and mind as well as the body and mind of others drop away.

Enlightenment is like the moon reflected on the water. The moon does not get wet, nor is the water broken.

When the fundamental truth of mind=experience=world is realized things are grasped directly. The idea that there are qualitative experiences that are distinct from the objects of experience reflects the same Cartesian duality of mind and world that underlies representational theories of mind; the Buddhist aim in criticizing this duality as a misconception is essentially spiritual. The Wittgensteinian position is clearly echoed in the Zenrin kushu, a 15th century Zen text, which describes consciousness as “Like a sword that cuts, but cannot cut itself; Like an eye that sees, but cannot see itself”: what is constitutive of the experienced world cannot be considered as part of, or as in, that world.

Non-duality as a response to the "hard problem"

2011-03-27T10:56:00.000-04:00

The respective ideas of Hume, Wittgenstein and Mahayana Buddhists are interrelated and are characterized by empiricism and naturalism. Not surprisingly the response they invite most prominently is a Kantian one. But Kant deduced that there had to be necessary preconditions for the possibility of representational experience: it was the representation of the world that had to be “conditioned.” None of these thinkers – not even Hume on my reading – defines experience as involving the formation of representations in the first place. Furthermore remember that the subject of this chapter is consciousness, and consciousness is not obviously amenable to a representational “explanation” even for those who are inclined to address intentionality that way. In any event if one balks at, say, the “solipsism” argument I certainly agree that it is a bit breath-taking, but I wouldn’t introduce it here if I knew of an argument that refuted it.

The present set of arguments, that will now be deployed against the “absent qualia” arguments that purport to show that there is a metaphysical problem about phenomenal properties, can all be attributed to some combination of Hume, Wittgenstein and/or Buddhism. The first two arguments are “soft”: they start with two respective points about the nature of language and conclude that private qualitative experience, whatever its ultimate ontological status may be, cannot be the subject of language. This is a soft conclusion because it sets aside the question of whether there really is anything that can coherently be regarded as “inner,” private experience. The remaining arguments are “hard”: they start with the inseparability of mind, experience and world and conclude that it is incoherent to posit the existence of phenomenal properties if these are taken to be mental properties distinct from the physical properties of the experienced world. However although the first two arguments are soft they do, if persuasive, suffice for the naturalization of psychology, because they demonstrate that qualitative experience, whatever that may be, could never have been a subject for natural science, and so is not a problem for natural science.

1) If language needs inter-subjective criteria of appropriate conditions of use then the phenomenal vocabulary, like all language, cannot function in virtue of referring to anything “private” to the individual. This argument is explicit in Wittgenstein, a case can be made that it is implicit in Hume’s verificationist epistemology. It is “soft”: it leaves the ontological status, if any, of qualitative experience alone. It naturalizes psychology the way that classical, early 20th century behaviorism naturalized psychology: an operationalist protocol excludes reference to the “inner” from science, so understood.

2) If the “meaning” of language/symbols is nothing more nor less than everything that has been accomplished through the use of individual, concrete tokens, then the phenomenal vocabulary cannot function by referring to anything private. This is functional-role semantics and it is unique to Wittgenstein among this group (although other philosophers, such as Pragmatists, also develop this sort of operationalist account of language). It is soft; the ontological status of qualia is not addressed directly.

3) If the self is nothing neither more nor less than the experiences of the world by the self, then there can be no duality between the “self” and the “world.” This is Wittgenstein’s “solipsism” argument, first presented at the end of the Tractatus, and the same idea is found in the Mahayana sutras of classical Buddhism and in Zen Buddhism. This is a “hard” argument: on this view the existence of phenomenal properties is denied. It is another argument that seems implicit in Hume, but Hume does give a very explicit argument to the same effect:

4) If experience defines the limit of what can be known, it is absurd to posit a distinction between the “mental” and the “physical.” Hume’s version is quite as hard as #3 because it produces the same conclusion that it makes no sense to speak of either side of the duality of mind and matter: both concepts collapse simultaneously. It is neither materialist nor idealist, but a position of non-duality. This view is shared by Berkeley.

5) Consciousness cannot be located in the world, so consciousness cannot be said to have any properties. This argument follows from #3. It is explicit (and elaborated at great length) in its Buddhist version but also clearly implicit in both Hume and Wittgenstein. It does not follow from this that consciousness cannot be a property. Just what we mean when we predicate consciousness of a thing is what is at question, although I take it as now established that the criteria for predications of consciousness are necessarily operational.

If the most tempting line of rebuttal to all of this is a Kantian one, remember that these arguments are here deployed to show that there are no phenomenal properties. This question about consciousness has been disentangled from the problem of intentionality. The motivations of the three sources of the set of arguments are varied: Hume fills out the radical implications of empiricist epistemology as far as they go; Wittgenstein has a vision about the foundations and limits of logic; and the classical Buddhists appear to take the metaphysical implications of non-duality both literally and seriously. Whatever one makes of these sources (or of my interpretations of them), it is at least fair to say that they place the burden on those who would say that there are phenomenal properties, metaphysically distinct from physical properties, to articulate reasons why anyone should think so.

However the discussion is far from over. Having assembled this set of arguments I now need to apply them to the various “absent qualia” arguments that have been the backbone of the critique of functionalism and the emergence of consciousness as a problem for cognitive science over the past thirty years.

My aim is not to show that operationalist theories such as functionalism are adequate to address the problem of consciousness; I am not “defending” functionalism from the “absent qualia” critique. My view is that intentional predicates must be handled operationally, while phenomenal predicates cannot be – that is, they cannot be to the philosopher’s satisfaction, notwithstanding the fact that all predication, to be intelligible, must adhere to intersubjective operational criteria. Functional descriptions abstract away from hardware: they include no physical descriptions. In the same way they abstract away from consciousness: they include no phenomenal descriptions. Of course this is true because there is no such thing as “phenomenal description” if by that one means reference to “private” experience. But a further point is that there is no reason to think that phenomenal experience is multiply realizable (supervenient), while intentional states are self-evidently so.

The point of the following discussions of the inverted spectrum problem and the zombie problem (both variants of the “absent qualia” problem) is not, then, to vindicate functionalism as a theory of consciousness. Theories don’t address pseudo-problems. The significance of the “absent qualia” arguments in the present context arises when they are offered as evidence that physicalism is ontologically incomplete.

Wittgenstein on Qualia

2011-03-15T11:28:00.000-04:00

Anyone who has read this far understands that Wittgenstein, for better or for worse, is the canonical philosopher who has had the most influence on the arguments that I am advancing here (even if I am merely Wittgenstein’s ape, as I rather suspect, from what I have read of him, that he would say I am). But when I started drafting this book Wittgenstein worried me. My strategy is to analyze the mind-body problem into separate problems that admit to separate solutions. But Wittgenstein seemed to be addressing both the problem of intentionality and the problem of consciousness, sometimes simultaneously. Perhaps I was mistaken to try to separate them?

Wittgenstein gives us a general treatment of language, and my method is essentially grounded in linguistic analysis as well. Metaphysics is brought down to Earth when regarded as a semantic inquiry: I don’t know, after all, what “primary being” is, or the limits of nature or anything like that. The only way to naturalize psychology is to develop a natural semantics for the psychological vocabulary. If the metaphysical theory of physicalism is right then our psychological talk has had natural, physical referents all along, and we should be able to determine what those are. Wittgenstein gives us, with his functional-role semantics, what is basically an operationalist account of meaning (“meaning is use”), and an operationalist semantic is a kind of naturalist semantic.

Now we can see the apparent problem: Wittgenstein argues that all language must have operationalist criteria of meaning, including the phenomenal vocabulary. But I have conceded that the “absent qualia” problem persuasively shows that operationalist theories of mind such as functionalism can’t handle the problem of consciousness. Isn’t there a contradiction in, on the one hand, embracing Wittgenstein’s argument that the word “blue” is meaningful (as it has intersubjectively verifiable criteria of use) while the construction “blue-for-me” is not, and on the other hand insisting that the naturalization of the phenomenal vocabulary requires a different treatment than the intentional vocabulary requires?

The tension is resolved by considering two other arguments of Wittgenstein’s, both of which are common to the Tractatus Logico-Philosophicus and the Philosophical Investigations, unlike functional-role semantics (developed in the PI) which represents the major difference between the earlier and later work. A popular misconception is that there is no continuity between Wittgenstein’s two major works; this is an effect of the strikingly radical operationalist treatment of “meaning” in the PI, and a consequently radical difference in method of composition. However much is missed when one misses the common themes.

Compare these quotations, first, the famous closing sentence of the Tractatus: “What we cannot speak about we must pass over in silence.” Then PI 296: “’Yes, but there is something there all the same accompanying my cry of pain. And it is on account of that that I utter it. And this something is what is important – and frightful.’ – Only whom are we informing of this? And on what occasion?” (Italics in original). Granting that at the end of the Tractatus he is speaking broadly about something he calls “mystical,” it is apparent that he takes ethical, aesthetic and spiritual experiences to be varieties of qualitative experience that, like pain, cannot be expressed by language. (This was the point, regarding ethical “propositions,” that W. was making when he got into that brawl with Karl Popper.)

The explicitly operationalist account of language in the PI develops from this earlier awareness of the limits of language (but note that this is not the same argument as the one tagged by his famous dictum “The limits of my language are the limits of my world.” That is the other argument, discussed below). If language is necessarily intersubjective (that is, worldly) then there must be public criteria for its use, but the insight that the quality of experience is inexpressible comes before, not after, this treatment of language. Functional-role semantics is a response to the inexpressible nature of qualitative experience.

So the great logical behaviorist turns out to acknowledge qualitative experience after all? The short answer is yes: he never denied it. At PI 296 his imaginary interlocutor is unchallenged when he says “this something is what is important.” Maybe the most important thing in life: remember that value itself is part of the inexpressible (and see Chapter Four). This does not involve him in a contradiction, although it needs some more consideration here.

One objection is that Wittgenstein is what was earlier called an “atheistic” or “philosophical” behaviorist: he denies that it makes sense to think of the mental in terms of something “inner” vs. the “outer” world. But aren’t qualitative experiences essentially “inner” in this sense? Not necessarily. The nature of qualitative experience is what is at question.

More importantly and more to the point of this discussion, Wittgenstein’s claim is not about qualitative experience, it is about language. The quality of personal experience is not expressible because of the intersubjective, public nature of language. Here is a link with the argument as deployed in Chapter Two: language (representation in general) does not exist “in the head,” either literally or figuratively. We saw in Chapter Two that the notion of the “inner” as something representational was vacuous, explaining nothing. Language (symbols, “meaning”) is something that exists only in the “outer” world. Thus whatever we make of qualitative experience, all language use has public criteria.

The two related arguments, that language must have public criteria for use and that what we cannot speak about we must pass over in silence, are sufficient to show that the problem of consciousness is not a problem for science (this point will be discussed at greater length below). But by themselves they give us only “agnostic,” methodological behaviorism, which may satisfy the empirical psychologist but will not satisfy the philosopher. The philosopher still has a question about ontology. In this discussion of Wittgenstein’s first two arguments I have been careful to use the phrase “qualitative experience,” leaving open the question of what it is of which such experience consists.

The third argument of Wittgenstein’s, one that is also common to the early and later work, goes further and demonstrates that “qualia,” understood as real properties that are non-physical properties, do not exist. It gives us the “atheistic,” philosophical behaviorism that we need to naturalize the phenomenal vocabulary. As with Hume it will turn out that there is no coherent distinction between “qualitative” experience and just plain experience. (Note also that in this section I am using the word “behaviorism” rather than the word “operationalism.” Since “behaviorism” is more the standard term in the Wittgenstein literature this makes it easier to situate the present discussion in that literature, besides being much less clunky. And anyway the arguments discussed so far are in fact about language; “behaviorism” in the sense that we can use that word to describe Wittgenstein’s view is not really a “theory of mind,” although it may be a theory of psychological talk.)

The third argument is known as the “solipsism” argument, and it is found in the Tractatus at 5.6 through 5.641. The most famous aphorism from this passage is 5.6, “The limits of my language mean the limits of my world” (italics in original), but for the present argument 5.621, “The world and life are one,” and 5.63, “I am my world. (The microcosm)” may make the point most clearly. In fact on my view 5.6 is frequently misinterpreted in a sort of obvious way, a recognizably Kantian way: if one represents the world linguistically (this interpretation goes), then the world as one represents it will be limited as a function of the limits of ones’ language. This is backwards. “The limits of my language” (italicized) is the phrase under analysis, and it can only mean (it is defined by) the limits of my world, which are, exactly as in Hume, coextensive with the limits of my experience.

5.632: “The subject does not belong to the world: rather, it is a limit of the world.”

5.64: “Here it can be seen that solipsism, when its implications are followed out strictly, coincides with pure realism. The self of solipsism shrinks to a point without extension, and there remains the reality co-ordinated with it.”

5.641: “Thus there really is a sense in which philosophy can talk about the self in a non-psychological way.
What brings the self into philosophy is the fact that ‘the world is my world.’
The philosophical self is not the human being, not the human body, or the human soul, with which psychology deals, but rather the metaphysical subject, the limit of the world – not a part of it.”

The word “qualia” is a “grammatical” (to use a word ubiquitous in the PI) reification of qualitative experience, which is constitutive of the world, “the limit of the world - not a part of it” (experience is not in the world). Naturalizing psychology does not require what cannot be done, naturalizing metaphysics. “The world and life are one.” As a living being I am constitutive of my world; my life and my world cannot be distinguished: 6.431: “So too at death the world does not alter, but comes to an end.”

The ontological idea of a Leibnizian parallelism between properties of the world and properties of experience makes no sense and it is the assumption of such a parallelism (of the coherence of such a parallelism) on which the alleged problem of consciousness rests. Kant, to be fair, is not so far from this insight himself (and Wittgenstein professed admiration for Kant): the rational mind, for Kant, is not a part of the phenomenal world. Only Kant’s followers did not heed his epistemological warnings.

This crucial Wittgensteinian appropriation of the word “solipsism” remains intact and unchanged decades later in the Philosophical Investigations. In the discussion of the multiplicity of uses of language (the fact that there are many different “language-games”) that opens the book Wittgenstein writes at #24:

“If you do not keep the multiplicity of language-games in view you will perhaps be inclined to ask questions like: ‘What is a question?’ – Is it the statement that I do not know such-and-such, or the statement that I wish the other person would tell me…? Or is it the description of my mental state of uncertainty? – And is the cry ‘Help!’ such a description?

Think how many different kinds of things are called “description”: description of a body’s position by means of its coordinates; description of a facial expression; description of a sensation of touch; of a mood.

Of course it is possible to substitute the form of statement or description for the usual form of question: ‘I want to know whether…’ or “I am in doubt whether…” – but this does not bring the different language-games any closer together.

The significance of such possibilities of transformation, for example of turning all statements into sentences beginning “I think” or “I believe” (and thus, as it were, into descriptions of my inner life) will become clearer in another place. (Solipsism.)”

All statements can be rendered “as it were, into descriptions of my inner life,” and this shows the actual vacuity of the allegedly significant distinction between “the inner life” and “the outer world.” The sense of the parenthetical “solipsism” is the same as in the Tractatus. It is important to see that Wittgenstein is not (as he admits) using the word “solipsist” in its usual metaphysical sense. In fact he inverts the ordinary sense of the word. Ordinarily the solipsist is understood to be saying that he only knows that one mind exists, his own (this is the Cartesian skeptical sense of the word). Wittgenstein is saying, with reference to certain uses of the first-person “I,” that one’s own mind is the only one that cannot be conceived as something in the world.

From the Blue Book (pp. 66-69):

“There are two different cases in the use of the word ‘I’ (or ‘my’) which I might call ‘the use as object’ and ‘the use as subject.’ Examples of the first kind of use are these: ‘My arm is broken,’ ‘I have grown six inches.’…Examples of the second kind are ‘I see so-and-so,’…’I’ have a toothache’…We feel then that in the cases in which ‘I’ is used as subject, we don’t use it because we recognize a particular person by his bodily characteristics: and this creates the illusion that we use this word to refer to something bodiless, which, however, has its seat in our body. In fact this seems to be the real ego, the one of which it was said, ‘Cogito, ergo sum’.”

In fact this use of the first-person pronoun does not “refer” to anything in the world at all. PI 404:

“’When I say “I am in pain,” I do not point to a person who is in pain, since in a certain sense I have no idea who is.’ And this can be given a justification. For the main point is: I did not say that such-and-such a person was in pain, but ‘I am….’ Now in saying this I don’t name any person. Just as I don’t name anyone when I groan with pain. Though someone else sees who is in pain from the groaning.

What does it mean to know who is in pain? It means, for example, to know which man in this room is in pain: for instance, that it is the one who is sitting over there, or the one who is standing in that corner, the tall one over there with the fair hair, and so on. – What am I getting at? At the fact that there is a great variety of criteria for personal ‘identity.’

Now which of them determines my saying that ‘I’ am in pain? None.

“Personal identity theory” is a branch of metaphysics: the study of the criteria by which we identify a particular entity in the world as the “self.” But the subject, on Wittgenstein’s version of solipsism, is not an entity in the world at all, insofar as we are thinking of the subject as having qualitative experience. The experiencing subject is metaphysically identical with the experienced world.

So far I have presented two versions of this argument, Hume’s and Wittgenstein’s. I am not piling up these various demonstrations that the problem of consciousness is a pseudoproblem in order to commit the informal fallacy of the argument from authority: I have my own reservations about Hume, Wittgenstein and empiricism in general but I am persuaded by these particular arguments that the alleged metaphysical problem of phenomenal properties is a pseudoproblem. It is striking that Wittgenstein’s “solipsism” is very close, perhaps identical, to arguments found in an ancient tradition with origins very far from those of empiricism.

Hume on Qualia

2011-03-06T11:37:00.000-04:00

Hume, a thoroughly modern anti-philosophy philosopher, argued that much confusion and intemperate speculation could be got rid of by acknowledging that knowledge, and therefore philosophy, had limits. There are what I call a “soft” and a “hard’ interpretation of Hume. On the soft interpretation, Hume flags an eternal question mark hanging over the limit of experience: we cannot know what lies beyond and we must simply accept that fact. This is Hume the cheerful skeptic, reassuring us that it’s alright that there are things we cannot know and cannot prove. On the hard interpretation, Hume defines knowledge as the output of experience. Belief is only habituation. In Of Miracles, for example, Hume is not telling the reader that Hume does not believe in miracles: he is arguing that the reader does not believe in miracles by virtue of the very definition of “belief.”

Hume says, "For as to the notion of external existence, when taken for something specifically different from our perceptions, we have already shown its absurdity" (Treatise 1.4.2, Of scepticism with regard to the senses). Hume is not a skeptic whose empiricism entails codifying Cartesian scepticism as irrefutable. To the contrary, Hume takes the position that Cartesian scepticism is a pseudo-problem. An idea that unifies the Treatise is that, contrary to the rationalists’ assertion that logical proof is the paradigm of knowledge, there are in fact no logical proofs for anything we “know” (and Hume is very much focused, as any good epistemologist should be, on the appropriate conditions for the use of the verb “to know”). To “know” something, for Hume, is to be habituated to have a certain expectation of potential future experiences by the regularities of past experiences.

The very idea of a distinction between “external existence” and “perception,” Hume says, is absurd. The idea that we are stuck inside our heads, unable to see around our mental representations, is absurd. At 1.2.6, Of the idea of existence, and of external existence, Hume writes: “Now since nothing is ever present to the mind but perceptions, and since all ideas are deriv'd from something antecedently present to the mind; it follows, that 'tis impossible for us so much as to conceive or form an idea of any thing specifically different from ideas and impressions.” It is meaningless to talk about some “reality” beyond the reality of experience since on the empiricist criterion of “meaningful” a statement is significant to the extent that it can be confirmed or disconfirmed on the basis of experience. This is exactly Berkeley’s view, stated in less paradoxical language: the Humean version of the argument that the problem of phenomenal properties is a pseudoproblem hinges, as Berkeley’s version does, on the absurdity of stating that there are physical properties when these are taken to be properties separate from the properties of experience.

This is not at all equivalent to saying that there is an external world to which we do not have access, trapped as we are within the conceptual framework of our representation (remember it is Kant who insists on that): empiricism rules out any such speculation. When Hume says that there can be no proof of the external world he is simply iterating another example of his refutation of Cartesian rationalism: if there are no rational proofs of anything than the word “knowledge” cannot refer to beliefs grounded in rational proof as distinct from experience.

“The world,” understood in any meaningful way, refers to the world of experience. It is literally inconceivable that there might be a world distinct from experience, or experience distinct from the world. Technically the position is nominalist: “the world” is the name of the category of all experiences. And on that point, Hume, in a footnote to 1.2.6, explicitly cites Berkeley: “A great philosopher (Berkeley)...has asserted, that all general ideas are nothing but particular ones, annex'd to a certain term, which gives them a more extensive signification, and makes them recall upon occasion other individuals, which are similar to them” (1.1.7, Of abstract ideas: the “external world” is an abstract idea of this kind).

Perceptual states, on Hume's view, are not “copies” of external reality (this has been shown to be absurd by extension of the absurdity of the concept of “external reality” itself). Rather they are states of the body: the (physical) process of perception has caused a (physical) change to the body (the “impression”). Crucially the impression is not identical to the experience. The formation of the impression is one physical part of the larger physical event of experience. There can be no metaphysical distinction between the mind and the body for Hume, who denies the possibility of any metaphysical distinctions whatsoever (exactly as Berkeley does). When we talk about our “impressions” we are talking about states of our own bodies; this need not involve us in the concept of representation. This is why Hume says that we cannot even assume a numerical correspondence between impressions and “actual objects”: impressions, understood as the physical effects of physical causes, cannot be assumed to perform a representational function in the first place.

Aren’t we discussing qualia here, as distinct from mental representations? Can we sort them out? Yes: there are, on Hume’s view, no representations, but there certainly are experiences. Experiences don’t represent the world; they are constitutive of the world. So the qualities of experience are identical to the qualities of the world, nothing more or less. That is, if it makes no sense to speak of “qualities of the world” if these are meant to be distinct from the qualities of experience then by the same token it makes no sense to speak of “qualities of experience” either.

What remains is to decide how to talk (philosophy often comes down to making decisions about how to talk). Berkeley and Chalmers propose radical solutions: say that the world is constituted by “ideas” rather than by “matter” and say that the qualities of experience are non-physical properties, respectively. However, to accept Berkeley is to reject Chalmers and vice versa, because where Chalmers would codify the metaphysical distinction between mind and matter Berkeley would abolish it. I’m guessing most readers will agree that abolition is a better solution than codification, because codification amounts to simply throwing in the towel and conceding that naturalization is impossible. For myself, I am a staunch abolitionist.

Hume, writing with Berkeley well-digested, develops the essential argument without the outré metaphysical language. Hume collapses the subject-object distinction into the subject as Berkeley did before him. But Hume recognized that once the distinction was collapsed neither of the categories “materialism” or “idealism” made any sense. The distinction simply vanishes. If there are no “physical” properties when these are meant to be separate from “phenomenal” properties the argument works with equal force in the other direction as well. It is on this point that the early 20th century empiricists misinterpreted Hume so grievously, understanding him as a “phenomenalist,” one who holds that we can refer only to “phenomena” as distinct from the “actual” (else why use the word at all?). On empiricism properly understood there is no meaningful (semantic) distinction on which to hang the metaphysical language. This insight is also the crux of the next two versions of the argument, but both are worth considering in detail by virtue of differences in language and emphasis, and to cement the point.

Qualia and Operationalism

2011-02-27T14:09:00.000-04:00

“Phenomenology,” the study of the qualities of experience, has a long history in both Eastern and Western philosophy. In its modern European version phenomenology has two post-Enlightenment roots. First, in its claim that experience has its own structure that can (and must) be explicated in order to establish the foundations of epistemology, the phenomenology of Husserl and Heidegger is thoroughly Kantian (by way of 19th century German transcendental idealism), as are the subsequent “Continental” movements of structuralism, deconstructionism etc. (Merleau-Ponty, with his emphasis on the role of the whole body in defining the phenomenal field, is an exceptional character in this community, and I will have something to say about Sartre in the discussion of Buddhism below.) Second, modern phenomenology is a response to the dramatic development of modern science and particularly to the perceived threat posed to humanism by the potential triumph of empiricism and the resulting absorption of the study of human nature into physical science.

It is not hard to see, then, why the naturalist movement in philosophy of mind, primarily a movement of English-language philosophers and scientists, resisted acknowledging the troublesome significance of phenomenology through the middle of the 20th century. A partisan narrative developed where the “Continentals” were resolutely non-scientific (holding, as they mostly did, that phenomenology was wholly autonomous from physical science) and often anti-scientific while the “Analytics” studiously ignored phenomenology and developed materialist philosophy of mind as part of a larger interdisciplinary (and largely empiricist and scientific) movement that eventually came to be called cognitive science, and that for its first fifty years or so had a strong ideological commitment to operationalism, and to some extent still does. Only in the past few decades has “consciousness studies” become an active area for cognitive scientists.

This doesn’t mean that phenomenology didn’t bedevil the naturalists from the first. The first major operationalist movement, behaviorism, had many variants, a lively theoretical literature and was an impressive generator of experimental protocols, but as a popular psychology (a theory of psychology intuitively persuasive to the average person) behaviorism was never really even a candidate for widespread acceptance, and the essential (popular) problem was, without doubt, behaviorism’s manifest failure to accommodate ordinary intuitions about qualia.

The primary motivation for behaviorism was to make a science of psychology. The primary strategy was methodological: strictly hew to the methods of empirical science and ipso facto science will be the result. This operationalist ideology entailed the elimination of reference to “unobservables.” Behaviorism developed a semantic for psychological words that held that psychological predicates referred to intersubjectively observable dispositions to behave. There is more to be said for this approach than is commonly recognized nowadays; Wittgenstein, who had much to tell us about the problem of meaning, also advanced what I find to be persuasive arguments about qualia and I will return to him in what follows. However at the moment we want to see how behaviorism, popularly understood, floundered over the problem of qualia.

Consider the word “pain.” If we take the behaviorist line in its literal, popularly-understood sense the word “pain” refers to wincing, grimacing, certain vocalizations (such as “ouch!”) and so forth. One problem with this is that the set of behaviors that might be identified as pain behaviors is indefinitely large (that is, it is not apparent what parameters fix the extension of the set), and there are other problems, but the crucial problem in the current context is that most people have a strong intuition that wincing, grimacing and so forth are caused by pain, that is that the word “pain” in fact refers to the feeling of pain and furthermore that this feeling is playing a causal role in the production of the “pain behavior.”

Behaviorism’s more sophisticated descendent, functionalism, turned out to be no better able to handle the issue of conscious qualitative experience. Consider this problem for functional-role semantics, which holds that the “meaning” of a word is nothing more or less than what the speaker achieves by its utterance: imagine a person whose color spectrum is inverted. Where ordinary people see red, this person sees blue and vice versa. However, growing up in the same linguistic community, this person would use color words exactly like the rest of us. Ask the inverted-spectrum person to, say, go out to the car and get the blue bag and they will return with the correct bag just as reliably as anyone else. But, the defender of phenomenology argues, what everyone else means by “the blue bag” is the bag with that quale, which is the ordinary person’s experience of the color blue: and the “invert” does not have that experience.

Here one might respond by pointing out that we have no way of knowing if any two people experience “blue” surfaces the same way. This is Wittgenstein’s point with the analogy of the beetle in the box: it can’t be that the phenomenal word refers to an individual’s private experience. At this point the defender of qualia ups the ante. Suppose there was a person who behaved, responded and so forth in appropriate ways such that they seemed to take psychological predicates just as naturally as everyone else. Imagine further, however, that this person had no private experience: a non-conscious “zombie.” Surely, the argument goes, one couldn’t consider such a creature to be a “person”? Surely we mean by “person” a being that has some experience? Aldous Huxley in his novel Brave New World, an early critique of operationalism’s qualia problem, is making the same point: when the quality of experience comes to be considered simply insignificant for “psychology” then that discipline is no longer what most people would consider to be psychology at all.

This whole genre of thought experiments comes together as the “absent qualia” argument. The argument is that complete functional descriptions fail to capture the quality of experience just as utterly as complete physical descriptions do. One of the biggest successes in philosophy of mind in recent years has been the work of David Chalmers, who argued in The Conscious Mind that, faced with the problem of qualia, we have no choice but to concede that materialism is false and that reality includes at least two kinds of properties, physical properties and phenomenal ones.

The philosophy of mind community acknowledged the problem of consciousness in the 1970s and 80s through some seminal work by Ned Block, Frank Jackson, Saul Kripke, Thomas Nagel, John Searle and others. Prior to Chalmers the “mysterians” such as Colin McGinn had argued for a kind of epistemological (or “property”) dualism (we must concede that consciousness cannot be incorporated into physical science, but maybe we can concede this without giving up materialism). But Chalmers’ sporting brief for metaphysical dualism represents a kind of apotheosis for the problem.

I read Chalmers as writing in a Berkleyan spirit. John Locke elaborated a system of various “properties.” There were primary properties, the essential physical properties of the object; secondary properties, the causal properties of the object such that it caused the mental representation to be as it was; and tertiary properties, the properties of the representation (Locke would say “impression”). In other words a fairly messy tangle. Berkeley, whose views appear strange when presented out of context, made what was in fact a common-sense (and thoroughly empiricist) suggestion: if the mental representation (the “idea”) is the only thing that we, in actual fact, experience, and there is an intractable problem about the relationship between the idea and the “material world,” why don’t we cut the Gordian knot by simply saying that ideas are constitutive of the world, and be done with the problematic “matter” altogether? After all we can only know about the ideas. So let’s just call our ontology “idealism” and move on. Chalmers’ move is very similar: embrace mind-body dualism so that we can forget about it.

I appreciate Chalmers not only because he is audacious, but because he focuses on the metaphysics, which is where the problem and any possible solution of the problem of consciousness lie. The key strategic move in the present book is to point out that “mind” is a heterogeneous concept. Thus we have not one “mind-body problem” but (at least) two. Granting this we can apply different theories to different problems without self-contradiction. In the last chapter I advanced a version of meaning externalism as the right semantic of intentional predicates, to replace the representationalist account. The view that intentional predicates refer not to mental contents but to relationships between whole persons and their environments is essentially an operationalist view. At the same time I do not think that any kind of operationalism will do for phenomenal predicates; that is, I agree that the absent-qualia problem cannot be overcome by any operationalist strategy. The problem of consciousness needs an entirely different treatment than the problem of intentionality.

However the only sort of “dualism” that I am willing to consider seriously is the dualism of form and matter to which I appealed in the discussion of rationality (and I take that to be a major concession). The question of the form-matter distinction is an interesting question for general metaphysics (and physics), and it is at the level of general metaphysics that it will have to be resolved one way or another: it is not ultimately, I argue, a problem particular to the metaphysics of mind. So the hope for a natural semantic of psychological predicates is still alive, granting that human beings may be possessed, like everything else in nature, of formal properties that are different from physical properties. Other than that (admittedly major) caveat, it is my view that there are only physical properties. So I will now have to argue that there are no phenomenal properties. A successful argument will have to persuade the reader that the absent-qualia problem has been satisfactorily addressed.

In fact three arguments (or perhaps three versions of one argument) will now be presented, drawing from three separate canonical sources. As in the discussion of Plato in the last chapter, it is not so much my goal to explicate the canonical sources with an historian’s precision as it is to use some excellent philosophy as a springboard and inspiration. This does not mean that I am giving myself a license to anachronism or idiosyncrasy. I am simply asking the reader to consider the arguments (and the interpretations) on their merits as they pertain, if at all, to the problem of phenomenal properties. The second part of the chapter will again appeal to heterogeneity and explore the implications of recognizing that consciousness, unlike intentionality, is not a supervenient quality. When this is recognized it turns out that we can avail ourselves of a kind of materialist theory that fails when used to address intentionality

A Resolution to the Problem of Rationality

2011-02-13T13:03:00.000-04:00

To summarize, the proposal is that the property humans (and any number of other probably-existing forms of life) have of “being rational” is a formal property, “formal properties” understood as mathematical (relational) properties that can be formalized (another way of saying they supervene on physical things). If this is correct then the metaphysical problem will be about formal properties: is materialism incompatible with the existence of formal properties?

Form/matter dualism is the only plausible version of dualism that I know of, and Plato’s arguments for the immortality of the soul from the eternal nature of form are the only plausible arguments for dualism I know. One doesn’t get as much out of it as one might think. One doesn’t even get one’s very own soul, because there’s really only one indivisible soul. Not much of an account of freedom, either: being as rational as possible is being optimally free.

What can be said is that the present argument locates the problem of form in the general area of “metaphysics,” showing that it is not in any metaphysically unique way a particular problem for “philosophy of mind.” While that may seem a fairly innocuous conclusion I think it does have some merit. The conclusion shows that predicates like “rational” and “computational” need not entail reference to representations, only to formal organization (and isn’t that Fodor’s goal?) If this is right then the Platonic resolution to the problem of rationality is not only compatible with the operationalist elimination of mental representation, it reinforces it with the observation that formal organization is ubiquitous in nature. The argument that rationality is a formal property blocks human exceptionalism, when exceptionalism is argued for from the supposed (ontological) uniqueness of rationality.

I don’t know what I think about the cosmological question about the innate organization of the universe or the lack thereof. I don’t know enough. But I have made a little progress on the dilemma seemingly posed by Plato and Wittgenstein. The key move was to see that “mind” is a heterogeneous enough concept that different psychological predicates turned out to be about very different things. The technical expression of the dilemma was that although mental representations seemed untenable, rationality understood as grasping and respecting the logical relations that obtained between the propositions seemed ineliminable. If form is accepted into our ontology then we can see how logical relations are “built in” to states of affairs themselves. What would it mean to say that a Platonist was a realist about “states of affairs” if he or she didn’t think that states of affairs had the same logical relationships with each other as those shared among propositions?

The interpretation of form/matter dualism that I have developed here holds that there is only one ontological fact aside from the fact of the physical world itself. This is Aristotelean in that there is nothing other than the physical particulars, only they are formally organized to a degree that seems contingent (I take Aristotle’s substances to be like this). This view might be incompatible with a strict interpretation of materialism (like Daniel Dennett’s prohibition of “skyhooks”). For me that would not be traumatic. There is the question of just what a sophisticated physicist or cosmologist might say about what primary being is. That is a worthwhile question but unfortunately I fear that I may already have strayed too far from the metaphysics of mind. The short answer is that you will not find a great deal of unanimity.

Meanwhile the real caper here is to try to square the operationalist account of representation offered in the first half of the chapter with this Greek-revivalist story about rationality. The idea is that the operationalist picture of language as use is one that can be developed in the context, if you will, of a world with some formal organization. In fact locating formal organization in the world looks like another way to eliminate representations, since part of their justification was that their semantic contents were needed to explain logical relations.

Wittgenstein and Aristotle?

2011-02-06T15:53:00.000-04:00

I’m afraid that some readers will be growing impatient as they read the foregoing discussion of a kind of Platonic resolution to the problem of rationality. Hadn’t I just, in the first half of this same chapter, argued for an operational theory of intentional predicates? Not only that, but when one suggests that the non-physical property of “meaning” can be washed out of the ontology of mind and language (replaced with an externalist account of intentional predicates as describing relations between persons and environments), that would be about as nominalist as one could go, surely?

Maybe not. The Platonism that I am offering has only one element of basic ontology besides matter. Form is indivisible, not divisible; a unity, not a multiplicity. There is only one form really: only one (perhaps inexplicable) ontological fact beyond the fact of the existence of something rather than nothing. Putting the question of Plato and Aristotle’s own views of species as “fixed natural kinds” to the side in favor of a view of species informed by evolutionary biology, it can be seen that putative “forms” such as the property of “cowness” or “lyrehood” are not genuine examples of form. Some categories (types of species, types of artifacts) come-to-be and pass away.

In its Aristotelian version Platonic form-matter dualism becomes a kind of non-reductive materialism: primary being is substance, the unity of form and matter. From the doctrine of the unity of form, though, it appears that this must be a kind of “non-reductive formalism” as well, as every particular with a formal property has that property, not by virtue only of the formally-organized parts of that particular, but by virtue of the entire formal organization of the material world: all geometric shapes (for example) are tokens of the one thing.

We know that by this point Wittgenstein would be fuming, but as usual with him we might not be certain exactly why. Of course Wittgenstein would have none of this Platonic talk. “The idea that in order to get clear about the meaning of a general term one had to find the common element in all its applications has shackled philosophical investigation; for it has not only led to no result, but also made the philosopher dismiss as irrelevant the concrete cases, which alone could have helped him to understand the usage of the general term. When Socrates asks the question, ‘what is knowledge?’ he does not even regard it as a preliminary answer to enumerate cases of knowledge.” (Blue and Brown Books; italics in original). Wittgenstein’s operationalist account of functional-role semantics is an arch-nominalist position: there is human behavior, a highly-adaptive and plastic process that changes over time, whose constants are determined by the biological (probably the best choice) nature of the human body and the human “mode of life.” “Property” names (like all names) really pick out parts of language, and the criteria for the proper application of language are essentially operational. Insofar as this line is developed as a strategy to naturalize meaning I think it’s a good one.

But I have never thought that philosophy of mathematics was a particularly strong point for empiricists, and that is troubling considering that Wittgenstein devoted a considerable portion of his writings to the development of an operationalist theory of mathematics. In any event I am unpersuaded by Wittgenstein’s view that extending the known proofs of mathematics is nothing more than an elaboration of a kind of “language game,” specific to humans by virtue of our particular “form of life,” such that there was no such system of entailments until some human (for example) elaborated it. It’s counterintuitive: isn’t the fact, that we can work our way from one part of mathematics to another, evidence that mathematical reasoning is coherent? Doesn’t Wittgenstein’s ultra-nominalist view of mathematics overstate the possibility space: the different ways “mathematics” could go?

However, it may be that the two treatments of the two different parts of intentionality - an eliminativist, operationalist argument to the effect that mental representation/content is not part of the reference of intentional predicates, on the one hand, and an Aristotelean argument to the effect that rationality is nothing more nor less than a formal property and that formal properties, if they exist at all, are ubiquitous – are compatible. According to Wittgenstein there are no abstract entities, of course, but it is important to appreciate how far Wittgenstein went in his naturalization of meaning, and how central to this were his ideas about mathematics. Wittgenstein saw mathematical behavior as a “technique,” a technique for living. “Living” is the operational verb that replaces the Cartesian verb “knowing”: a case of knowing how rather than knowing that. Wittgenstein rejected the passivity of the representational theory and insisted on viewing language as a physical behavior that aimed at getting on with the business of life.

Granted that the Aristotelean world is one where every concrete particular is a union of matter and form, the “form of life,” understood as the vital activities of a being of that kind, would exhibit formal properties. In fact “behavioral ecology” develops an entire narrative, largely mathematical, about the ratio of nutrients per square meter to species population per square meter, showing the correlations between these functions and genetic transmission and so forth. The human “form of life,” if it is anything at all, is a product of the same natural history as that of the human organism; the rationality of humans, like the harmony of musical instruments, is an expression of form.

Within this form of life, that stress made no more emphatically by anyone than Wittgenstein himself, the criteria for use of psychological predicates can be understood operationally such that no mental content is implied. In fact Wittgenstein and Aristotle come together in a sense around “form of life” or what Aristotle would call the telos of an organism. They both suspected that explanations about what sort of thing a thing was and what sort of life a thing led were more informative than explanations about what sort of things a thing thought. Wittgenstein thought that the notion of mental content made no sense. I take the argument from the form-matter distinction to show that “computation” need not necessarily entail mental representations; organizational complexity equivalent to the syntactical complexity of language is found throughout nature. Finally, Wittgenstein’s functional-role semantics and Aristotle’s teleological account of biological explanation are very similarly motivated. They come together in the area where functionalism replaces reductive materialism as a response to the supervenient nature of the functional property.

Materialism and the Two Existential Questions

2011-01-30T21:10:00.001-04:00

It is hard to see the import of a metaphysical argument that has no epistemological implications. If dualism about body and mind is correct an interaction problem will have to be dealt with. By the same token if materialism is to be taken seriously it will have to provide a naturalized account of causal explanation. I take this to mean that to espouse materialism is to commit oneself to the view that a “closed” physical explanation, that is an explanation that refers only to physical causes, is possible. Many materialists understand this to mean that there can only be one “existential question,” if an existential question is one that might not have an answer: “Why is there something rather than nothing?” The idea is that there must be absolutely nothing inherently organized about the something that exists, because materialism is the bare claim that only matter exists and must accomplish everything starting from that sole axiom. Remember, too, that early modern materialism was closely linked with empiricism, forged in opposition to the classical tradition of Neo-Platonism, Christianity and rationalist philosophy and programmatically hostile to metaphysics.

Consider, for example, the argument traditionally called “the teleological proof for the existence of God” or more recently “the intelligent design argument.” Put in currently popular terms, the argument is that the complex design of the natural universe is evidence for an intelligent designer. In this context there is a significant difference between this sort of view and double-aspect theories that see mind and matter as one ontological being, under two kinds of description. (In addition to Spinoza many Hindi and Buddhist philosophers develop versions of double-aspect theory.) In so far as the design argument is an argument meant to demonstrate the existence of another being, the intelligent agent nominally responsible for the design of nature, the argument fails. The design argument starts by asserting that any finely-organized entity must have some sort of explanation. In the case of the natural world, an evidently finely-organized entity, the explanation offered is that there exists an intelligent designer. But the advocate of the intelligent design argument, in so far as he or she takes the argument to show that an intelligent designer ontologically distinct from the natural world exists, now looks committed to the need for an explanation of this finely-organized entity in turn.

To read this back into theory of mind, a materialist theory of mind has to get to mind from no-mind. The intelligent design argument fails because it is intelligence itself (in Platonic terms, the intelligibility of the universe) that we are trying to explain, and pushing the problem back a step is a failure to explain, just as saying that representations are interpreted in your head fails to explain how you, an actual person out in the world, actually interprets anything.

However, it may be that some materialists have over-reacted to the danger posed by the slippery slope that supposedly leads from recognizing that the physical universe may have some innate organization to…what? Say, full-blown Roman Catholicism? Perhaps it is simply a matter of two existential questions, not one. In addition to “Why is there something rather than nothing?” maybe “Why is the something that there is organized such that complex physical systems with formal properties arise?” To come to accept that the universe is a formally organized place can be an entirely secular resolution, after all. Materialist biologists arguing against creationism in the public schools don’t want to work themselves into an even weirder position than that of their religiously-motivated, intelligent design-espousing opponents.

The question then becomes, does accepting that there are two existential questions, not one, entail conceding that materialism is false? I think that in a way it does. If it makes sense to say that formal organization a) exists (“obtains”: I take the Aristotelean view that formal organization, if it is real, is a feature of the physical universe) and b) is a further, contingent fact (that is, there could have been a physical universe that was not formally organized to any degree) then materialism in its most orthodox version is false. I will go so far as to say that this appears to me to be the most plausible resolution to the problem of rationality, and that I do not think that it would be the end of the world if materialism were modified in this way. It is often pointed out that contemporary physics’ picture of “matter/energy” is now so strange that the concept of “materialism” probably can’t do much reliable reductive work anyway. And it is striking that physics has become more and more mathematical as the modern movement of physics has progressed over the passed one hundred years or so.

I think, though, that I can have my resolution to the problem of rationality without settling the cosmological question about the existence (or lack thereof) of innate universal order. The orthodox materialist might be able to explain how complex, self-replicating forms emerged from random, chaotic interactions, such that there is no need for “innate order.” Or materialism may fail to do this. It is enough for my thesis if formal properties are ubiquitous in worlds where rational beings evolve. How those worlds got that way is irrelevant to the point, which is that rationality is (just) another formal property and, although rational beings may be breathtaking examples of finely-formed entities, they are not therefore ontologically distinct from the rest of the physical universe.

Plato and the Metaphysical Problem of Rationality

2011-01-24T07:56:00.000-04:00

Plato, like Kant, was reacting to contemporary currents of thought that he regarded as dangerous. He took seriously an epistemological problem that he thought was posed by Heraclitus’ doctrine of universal flux (Plato disregards Heraclitus’ view that “all things happen in accord with the divine Logos” and sets Heraclitus up as the materialist foil to Parmenides). In a world where nothing was eternal, unchanging and universal, knowledge with those qualities was also not possible: it had no object. To try to compose a description of an ever-fluxing world was like “shooting after flying game” (as Socrates says in the Theatetus). That sort of knowledge was a snapshot of a mere moment, quickly passed. Plato’s strategy for addressing this epistemological problem was metaphysical: identify the eternal, unchanging and universal object.

Plato also opposed the reductive materialism of Anaxagoras and the other Melisians, early natural scientists (Aristotle, who shared Plato’s opposition to reductive materialism, addresses Democritus’ atomism). The word “reductive” in the phrase “reductive materialism” is also epistemological in its import: the idea is that macro-level phenomena (such as the minds of persons) will ultimately be explained in terms of micro-level phenomena (such as the parts of bodies). Materialism understood this way is committed to the view that properties are caused by matter. The materialist answer to the question “Why is this property what it is?” is “Because the underlying matter is what it is.” Both Plato and Aristotle argued that causation (and thus explanation) ran the other way.

Plato and Aristotle hold respective versions of the form-matter distinction, the view that basic ontology includes both form and matter. Plato’s version is patently dualist. He holds that form is primary being, that it is mind- and matter-independent, and that formal being acts on material being such that matter can only be said to be something to the degree that it is involved in form. Aristotle, objecting to what he saw as Plato’s ontological promiscuity, argued that substance, a union of matter and form, was primary being. Among other advantages this resolved the interaction problem that afflicts Plato’s dualism. On the other hand, the price of collapsing matter and form together into substance in this axiomatic way was that one had to accept that primary being was heterogeneous. This is counter-intuitive, but that doesn’t make it wrong. Close attention to Aristotle’s metaphysical differences with Plato is rewarded with any number of insights into subtleties of the mind-body problem (for example notice the resonance with Spinoza). We will return to Aristotle and De Anima, his own great work on the philosophy of mind, in Chapter Four.

However I will argue that these differences, significant as they are, are not relevant to the present, relatively broad point I want to make about the form-matter distinction, materialism, and the problem of rationality. Ultimately I’m more of an Aristotelian than a Platonist, but I think Plato’s more explicitly dualist discussion makes this broad point best so I will discuss two passages from Plato, the “analogy of the sun” at Republic 507b-509c and the treatment of the materialist argument that “soul is an attunement of the body” at Phaedo 93a-94e.

The Sun, Plato says, makes the universe a visible place. Our eyes take advantage of this (Plato and Aristotle resisted Empedocles’ arguments for natural selection, which they saw as reductive, but the reader should join me in helping ourselves to evolutionary biology wherever it helps to fill things in here). We can see each individual visible thing because the whole universe is suffused with that one element, light, which emanates from the Sun. Analogously Plato claimed that something he called “the Good” suffused the universe with order and made it an intelligible place. The Sun is to vision as the Good is to rationality: both vision and rationality are possible because of the existence of a more general feature of the universe. Plato takes the analogy farther. The Sun’s light is necessary for the growth of plants and the Good’s order is necessary for the emergence of definite (definable, intelligible) things. The Sun is the source of warmth; the Good is the source of value. Darkness is the absence of light; badness is the absence of order.

Describe any concrete particular thing. You will describe it (you can only describe it) in terms of its properties. Concrete particulars, as Heraclitus pointed out, are constantly coming-to-be and passing away. Properties (forms, universals) are eternal. The epistemological challenge posed by Heraclitus’ doctrine of universal flux is met with the Platonic doctrine that formal knowledge (knowledge of formal properties), as distinct from material knowledge (knowledge of concrete particulars), constitutes true understanding.

However there are properties and then there are properties. I stated at the beginning of the book that I don’t like a lot of loose talk about “properties” and that ultimately I think that physical properties are the only kind of properties that there are. If I am going to qualify that at all (and at the end of this discussion you will be left with your own judgment to decide how far I have gone in that direction, and if too far), then I had better try to be a good deal more precise about what I mean by “formal properties.”

Consider two putative properties: the property of “cowness” (or “being-a-cow” or what you will) and the property of circularity. According to Plato, as matter approaches nearer to form it comes to be something, “being” meaning “being intelligible,” which to Plato is a legitimate ontological category (Plato posits degrees of being, contrary to the materialist’s zero-sum understanding of being). However, while there are certainly well-formed cows and malformed cows, even a cow still-born with deformity is a cow (if someone comes into the barn and asks, “What is that?” the right answer is “That’s a cow.”). Plato and Aristotle thought that species were fixed natural kinds (to use the standard phrase), but we (well, I) don’t think so: species are the kinds of things that come-to-be and pass away, just as individuals do. With circularity the situation is different. Being a circle just is having (instantiating) that property, and there is a threshold of trueness short of which we will say that the concrete particular isn’t a circle in a sense that it cannot be said, of any animal born of cows, that it “isn’t a cow.” Once a cow, always a cow, but a concrete particular can gain and lose the property of circularity.

The extension of the set of all formal properties can only be understood in the context of Plato’s central metaphysical thesis of the Good. Plato is clear on the difference between material being and formal being. Material being is divisible (Socrates’ body can be chopped up into pieces and scattered like leaves or burnt and blown away like smoke), it is a multiplicity (I am one body, you are another), and it comes-to-be and passes away (“All men are mortal, Socrates is a man…”). What part of reality is indivisible, a unity (oneness), and eternal?

Imagine (if this is the sort of thing that can be imagined) that one’s sole mathematical practice was to name one set, {x,x}, let’s call it “2.” Now we reflect on our named set and it occurs to us that we need a name for the constituent set, {x}, so we call it something: “1.” It is now impossible not to notice a pair of functions, “+” and “=.” From these we will inevitably get to the other functions, and we also now have a practice of naming all sets; we have the set of natural numbers. In fact all of mathematics is entailed by any part of mathematics. Mathematics cannot be cut into pieces. To have it is to have, at least implicitly, all of it, including all of those proofs that no human has as yet discovered (it is mind-independent). Nor can any part of mathematics be considered, as physical objects can, in isolation from the rest. I can imagine a universe consisting only of this desk chair floating in the vast emptiness of space (I think), but if the proof of the infinity of prime numbers is floating out there, so is all the rest of mathematics. It is one, not a multiplicity of separable propositions. Not only that, but it looks like it is floating out there, since we discover the entailments. And those proofs would be valid, undoubtedly, whether or not there was any matter and energy at all. Mathematics is indivisible, a unity and eternal.

At this point it is possible to be more specific about what a “formal property” is. I take formal properties to be mathematical properties, essentially. For what it’s worth, I even think that this may not be far from Plato’s actual theory, reflecting as it does the metaphysical influence of Pythagoras and Parmenides. To say that a thing has a formal property is to say that there is an aspect or part of that thing that can only be described in terms of mathematical or logical relationships that can be formalized without reference to the contingent physical properties of the thing. For example the property of circularity is a formal property. The set of circular things includes wooden things, clay things, bone things and metal things, but circularity is supervenient: its mathematical description is about the spatial relationship between one of its parts and another and this formalizable (mathematical) relationship does not “reduce” to any contingent properties of wood cells or clay particles etc. That is, “formal properties” are properties that can be formalized. All formal properties are supervenient on matter: there is no physical criterion that fixes the extension of the set of physical things that instantiate the property.

Another way of saying the same thing is to say that any physical object might potentially be involved in any formal property. Formal properties are universal (sometimes they are called “universals”). A critical point here is that strictly speaking there is only one formal property, that property that the universe has of being formally organized by the Good. To speak of a plurality of “forms” (“circularity,” “rationality”) is figurative. There is only one form in which all formally organized things participate; only its expression in matter is multifarious as for example in the various geometrical shapes. (In the next section I will discuss whether and how much this literalist Platonism can coexist with materialism in general and particularly with the Wittgenstein-influenced eliminativism about mental content that I sketched above.)

At Phaedo 93a-94e Socrates is responding to a kind of materialist theory suggested by Simmias. Simmias acknowledges that Socrates can raise difficulties for the identification of the soul with the body by pointing out apparently metaphysical differences between them (for example with the argument from “recollection,” which is Socrates’ term of art for innate knowledge), but Simmias argues that the soul might nonetheless be a kind of “attunement” of the body. This is an emergentist view: when all of the physical properties come together in the right way, a non-physical property emerges, not identical to but dependent on (caused by) the underlying physical properties. Emergentism is a creature of that murky area, populated by refugees and smugglers, where “non-reductive materialism” and “epistemological dualism” share a hopelessly porous border. People who wind up here wanted the goodness of materialism without the badness. Plato’s (dualist) response to the emergentist challenge provides the last link in my argument for a Platonic resolution (I don’t say “solution”) to the problem of rationality.

Consider a musical instrument and the harmonious sounds it makes. On Simmias’ view the harmonious sounds are caused by the particular physical properties of the instrument. Thus while it’s true that the harmony is not identical to the body of the instrument, it is also true that with the passing away of the instrument’s body there will be a simultaneous passing away of the harmony. Socrates responds that harmony is a formal property. That is, harmony itself is not more or less harmonic, any more than circularity is more or less circular. It is physical particulars that can gain or lose circularity, gain or lose harmony. One can get more or less harmonious, but once a lyre always a lyre. The harmony, then, is nothing particular to the lyre; the lyre may have a particular sound in some other aspect, but qua harmonious it participates in the same harmony as every other harmonious object. “Harmonious” is the type, and the extension of the set of physical tokens (musical instruments) cannot be fixed with physical criteria; harmony is formalized in musical notation.

In fact causation runs the other way. Instruments were developed (over a more or less long period of time involving trial and error) according to how well various materials, constructions, forms and so forth achieved harmony. Musical instruments come to be, and are caused to have the physical properties that they have, by virtue of the principles of harmonics. Music is a clear case where the formal property (of harmony) is the antecedent cause of the formation of a set of physical particulars (musical instruments) that exist because they participate in the property. If someone asks, “Why is the lyre shaped like that?” the right answer is, “Because that shape is harmonic.”

Here is the argument towards which I have been working: Consider the three properties circularity, harmony and rationality. They are all formal properties: they are all supervenient and they are all formalizable. The property of rationality is a very fancy formal property compared to circularity, to be sure. But rationality does not constitute, relative to circularity and harmony, any new ontological category. A circular object is an example of an object that possesses both physical and formal properties (in fact both Plato and Aristotle thought that all physical objects possessed formal properties). Meanwhile “immortality of soul” is neither more nor less than “immortality of form.” Remember that ontologically speaking there is only one form: form is a unity, matter a multiplicity. That both a rational human and a circular piece of chalk are involved in the same dualism of form and matter seems difficult to dispute.

Although Plato never, to my knowledge, uses panpsychist language to the effect that non-living objects such as pieces of chalk have souls (a view more explicit in the double-aspect ontology of Spinoza), neither does he say they don’t. Anyway he could be using the word “soul” to refer specifically to rationality and that wouldn’t affect the basic argument here. Socrates comforts his human friends with the argument that humans are constituted out of both matter and rationality, a formal property, and as form is immortal, so that element of humans will never pass away. But obviously a circular object is constituted out of both matter and circularity, and so anything said about a rational object also follows for a circular object as both are understood as possessing a formal property, and the argument turns on the immortality of form.

The result is that what we have been calling “the problem of rationality” turns out to be an instance of a quite general metaphysical problem, the form/matter problem. Now I can discuss the “resolution” to the problem of rationality that this constitutes, but first there are two discussions that are owed to those who have read up to here. The first discussion is about the relationship between the form-matter distinction and materialism: is materialism unable to give a naturalistic account of the formal properties of the universe, including the mind? The second discussion is about whether or not an eliminativist, externalist solution to the problem of representation (such as the one I proposed in the first half of this chapter) can coexist with a Platonic resolution to the problem of rationality.

Plato is not Kant

2011-01-16T11:43:00.000-04:00

Kant’s self-styled “Copernican revolution” was a turning inward, to the study of the mind, for solutions to the perennial problems of philosophy. Kant is, among other things, something of a reactionary. Writing at the end of the century of the Enlightenment he sought to defend Christianity, freedom and morality from the threat posed, as he saw it, by empiricism’s atheistic, amoral worldview. Particularly Kant tried to devise an antidote to Hume, and realized that Hume’s Lilliputian psychology, with its denial that anything like the “mind” could even be said to exist beyond the “impressions” caused by sensory experience, was a weak spot in the empiricist argument. Developing an ambitious account of the way the mind organized the “sensory manifold” with a conceptual framework of its own (including the “concepts” of space, time, cause and effect, multiplicity etc), Kant contained the world as understood by the new natural science within a mental representation: the “phenomenal” world was the world as represented by the rational mind, not to be confused with the actual, “noumenal” world.

Kant’s revolution has practically defined philosophy, certainly popular philosophy, ever since. From the German-language transcendental idealists, psychoanalysts, phenomenologists and critical theorists to the French-language existentialists, structuralists and deconstructionists to the English-language phenomenalists, language philosophers and, yes, cognitive scientists, it is hard to find any major philosophical movement of the last two hundred years that does not reflect the influence of Kant. He is one of the few canonical philosophers, whose influence can be seen in the views of the general public, including a great many people who have never heard of him or who do not appreciate that their own views are substantially Kantian. His message that our own minds broadly condition “how we see things” is congenial to a modern world of great cultural, ethnic and political diversity (notwithstanding the fact that Kant himself thought that the rational mind, qua rational, was the same for all).

Although Kant was engaged in a close struggle with Enlightenment empiricism his revolution was not a turning back of the clock. He presented an alternative not only to the empiricists but to the classical metaphysical tradition as well. The eclipse of explicitly metaphysical philosophy for much of the 20th century is of course due to some extent to the cultural impact of modern science, but it also reflects Kant’s core argument that psychological epistemology is first philosophy. What license have we, stuck as we are inside our heads, to make metaphysical speculations about “the external world”?

As a consequence of this it is now difficult for us to appreciate Plato, that most metaphysical of philosophers. So deeply and widely internalized is Kant’s thesis - that the conceptual order of the world is a projection from the mind onto the world - that many people simply cannot hear Plato anymore. In fact many people, even some philosophy professors and certainly a great many students, simply believe that Plato is Kant: the Platonic universals are Kant’s categories. What else could they be, when it is taken as axiomatic that the mind constructs a representation of the world? A smart student, in a typical but relatively explicit exchange, insisted that there was no such thing as the property of circularity or, for that matter, the set of circular concrete particulars: our minds create such categories out of whole cloth, apparently: and this was the view that he ascribed to Plato (he thought that he knew nothing of Kant). He was not at all impressed when I pointed to the two identical circular ceiling fans. Similarity itself, he understood, was a projection of the mind, a feature of the mental representation. As for the textual evidence (which in reality is clear and systematic), Plato is gnostic, all riddles; no one can really understand him. After all, he can’t mean what he is manifestly saying. Attempts to disabuse people of these notions, when not rejected out of hand, are met with bewilderment, anger, and various stages of grief and disillusionment. The slightly more sophisticated perceive that Plato is a bad, bad influence, putting us all at risk of totalitarian dystopia with his irresponsible foundationalism. One of my students told me that her law professor informed the class that he would have voted for Socrates’ execution.

Ah, well. Forgive this old classroom veteran my hobby-horses. Suffice it to say that, for good or ill, Plato is not Kant. Plato is making assertions about the ontology of the universe (of being); just what Kant and his followers claim cannot be done. Listening to what Plato has to say will help us to develop a resolution of the problem of rationality, at least insofar as this problem is one of the mind-body problems. I am not here trying to determine exactly what Plato the individual man actually believed in its fine points. I am not an historian of philosophy. My interest in Plato is the same as my interest in Hilary Putnam or John Searle or Jerry Fodor or for that matter the person sitting next to me on an airplane: if they have interesting ideas that inspire me in my own thinking I am grateful for the acquaintance. The reader whose principal interest is in contemporary philosophy of mind can rest assured that that is my principal interest as well, and that I am not wandering off into exegesis for its own sake. It’s just that I sincerely believe that Plato is the best exemplar of the best argument for resolving the problem of rationality.

Spinoza and Fodor

2011-01-09T13:21:00.000-04:00

Spinoza wrote during the transitional 17th century, when the medieval use of the term “God” as a term of art in philosophy overlapped with the early modern interest in the new science, particularly the mechanistic physics that grew out of astronomy and achieved its greatest expression in the work of Isaac Newton at the end of the century. Spinoza took a particular interest in the mind-body problem within the century’s larger preoccupation with reconciling the well-ordered, necessary world revealed by logic and mathematics with the seemingly chaotic, contingent world observed by empirical science. Philosophers of this period are often accused of hiding a thoroughly modern secularism behind religious language so as to avoid trouble with the authorities and to make their modern doctrines go down more easily, but this is a specious interpretation: these thinkers were developing modern ideas out of the old and it was a confusing and difficult process. One has to learn their philosophical language and try to understand their use of the word “God” as a technical term.

Spinoza’s core metaphysical argument is that God can have no limitations: to say that there was anywhere a boundary such that God was on one side and not on the other violated God’s property of universality (notice that one can substitute “mathematics” for “God” here with no loss of sense). Spinoza concludes that the universe (he often uses the term “nature”) is identical to God. It follows that the universe is necessary and perfect. The idea is that the causal processes of nature, seemingly full of contingency and randomness, actually unfold following mathematical necessity (in this regard Spinoza’s views are very close to Newton’s). Humans cannot see this directly due to our own limitations, but we can cultivate an attitude appropriate to the insight.

From this central doctrine Spinoza developed what is commonly called a “double aspect” theory of the relationship between the mind and the body. Everything (the universe) is both the mind and the body of God. Thus everything comes under both a mental and a physical description, which are two ways of looking at the same thing. A benefit of this view is that there is no question about either mental-to-physical or physical-to-mental causation; nor is there any question of choosing between dualism, idealism or materialism: Spinoza presents a monism where the only item of ontology is “God.” Both our mental nature and our physical nature are in fact aspects of our “Godly” (that is, rational) nature. This helps to make sense of the seemingly bizarre doctrine of “synchronicity” developed by Spinoza’s successors Leibniz and Malebranche, which expresses essentially the same idea: the mental and the physical are both explained by a common, antecedent source, which also explains how they are linked (for Spinoza they are one).

Spinoza’s metaphysics leads him to the strikingly modern position of rejecting dualist language about, for example, the mind being the controlling cause of the body’s movements (the ghost in the machine). But also Spinoza rejects the idea that the physical world (the “mode of extension”) is anything random or otherwise contingent. The physical/extended world has structure that corresponds to the mental world. His insight that fine-grained physical processes in the body instantiate the fine-grained processes of the mind (the body is “the object of the mind”) is achieved not by eliminating rationality (as Hume attempts to do) but by merging the rational and the physical.

The contemporary philosopher Jerry Fodor develops a similar line. Fodor understands that physicalism requires that the non-physical property of intentionality be washed out of the ultimate account of things, but he is convinced that mental content is ineliminable: two positions that would appear to be mutually exclusive. What account of mental representation can be given that does not involve us in reference to the semantic property? Fodor proposes to translate semantic properties into syntactic properties. The syntactic structure of the proposition (that is, of the mental representation that is implicit in the intentional attribution) maps on to the computational structure of cognition, which can be cashed out at the machine-language level. A “machine-language” isn’t really a language at all, in the sense of “language” as a symbol-system with semantic content. In the case of computers, binary code (1s and 0s) represents the physical state of the electronic gates in the microchips (open or closed). As the creators of computers we can explain the words and images on the computer screen in terms of the underlying physical process.

Uncovering the machine-language of the nervous system looks like a holy grail for cognitive science. But computers are artifacts that, ultimately, move symbols around for human beings to interpret, so the computer analogy doesn’t go through: actual mental content of the sort that (as Searle demonstrates, convincingly to my mind, with the Chinese Room) computers utterly lack has to be explained without appeal to an interpreter. The mental must be explained wholly in non-mental terms. Computers have the mental already built in: their human users. Fodor’s most expensive proposal is his idea that the causal role of mental content can be explained wholly in terms of the syntactical properties of the representation: that syntax alone can perform the function of sustaining and respecting the logical entailments between the propositions. This requires that he rejects meaning holism in favor of meaning atomism: like immune system antibodies, each mental concept must be latent and autonomous. This is also necessary if we are to keep cognitive psychology (as Fodor believes we must) “in the head.”

I have already expressed my sympathies for externalism and my eliminativism regarding mental representation. However I come not to bury Fodor but to praise him. Fodor has the same insight as Spinoza: to understand the identity of the mental and the physical requires that we understand not only the mental as, in some sense, physical but also the physical as, in some sense, mental. The problem of rationality, unlike the problem of representation, will require something like the double aspect approach. Spinoza proposes the aspects of mind and body, Fodor proposes the aspects of semantics and syntax. That Fodor is a realist about representations and I am an eliminativist does not turn out to mean that we fundamentally disagree. Specifically I don’t think that syntax entails symbol entails semantics, a line of criticism that many materialists would take against Fodor. However, while Spinoza and Fodor both point the way to the resolution of the problem of rationality, to actually get there we must now consider the metaphysics of one of the greatest of all philosophers.

The Problem of Rationality, the Other "Problem of Intentionality"

2011-01-02T12:55:00.000-04:00

What is the property of “rationality”? Let us say that it is a property of a rational being such that that being can make general use of an understanding of logical and mathematical functions and relationships. Rationality is a necessary component of agency (Kant stresses this): the reasons for the action can only be described with respect to the logical implications that obtain between them (and thus Kant offers a “coherence” theory of truth). Of course ultimately there are physical reasons for everything: one has to eat. “Reason is the slave of the passions,” wrote Hume, and he is right. However, the ability to grasp logical entailments is, as Chomsky, a self-styled “Cartesian rationalist” would say, “generative,” just as logical relationships are themselves non-specific. “If X, then Y.” “X.” The inference to be made from the coincidental truth of these two propositions is the same regardless of what “X” and “Y” are. Humans are able to formalize math and logic, abstracting from concrete incidents in order to be able to study these formal relationships as such. And, although my sympathy with Hume is great and my antipathy towards human exceptionalism equally so, the fact is that empiricism has a hard time dealing with mathematical and logical thought (I will use the term “rational” to refer to this kind of formal thinking for the sake of economy; in any event I think that logic and mathematics are the same thing). The kind of knowledge generated by rational thought (for example the proof of the infinity of prime numbers) appears to go beyond anything that could be explained as the product of interaction with the environment.

The idea that the propositional contents of intentional states are the bearers of logical relationships with each other is an expression of this problem: physical states and processes don’t appear to have any logical relationships whatever, whether they are “in the head” or not. However, this problem is a separate problem from the problem of mental representation, for whether one endorses a representational model of the mind or not one must still acknowledge the supervenient nature of rationality.

In fact the multiple realizability of rationality is the core metaphysical problem here. The problem can be stated this way: there do not appear to be any physical criteria that fix the extension of the set of rational beings. Flipper the dolphin, Max the Martian, Hal 2000 the intelligent artifact and I all take intentional predicates that entail the rationality assumption even though we’re not all made of the same sort of stuff. Although all four of us have physical properties sufficient to instantiate rationality, none of these physical properties are necessary for rationality (since we don’t share them). The extension of our set is indefinitely large.

A common popular view is that emotional experience and feeling are what make the naturalization of psychology so difficult, but philosophers and psychologists from the ancient Greeks on have more frequently taken humans’ rational capacity as the principal warrant for dualism. In fact both of the two greatest rationalists, Plato and Kant, saw emotions as fundamentally physical in origin, “passions” of the soul (like hunger) that sprang from our contingent natures as physical things. Plato and Kant also agreed that the capacity for rational thought was the key to human freedom, which they defined as freedom from the coercion of physical cause-and-effect relations. Both thought that qua embodied beings humans were mere material things, but through participation in transcendent rationality humans became (or could become) more than mere things.

I doubt that being motivated by purely logical thoughts (whatever that would be like; I suspect it’s inconceivable: and see Chapter Four) would result in anything recognizably like our usual conception of “freedom.” After all logical entailments follow necessarily from their antecedent propositions, so that to the extent that one is motivated by purely logical considerations one does not experience choice (or possess any psychological individuality for that matter). But putting the question of freedom aside, it does look like emotional experience is part of consciousness (emotions are essentially phenomenal) whereas rational thought is part of intentionality. Anyway that view, and the view that phenomenal “properties” of mind are, ontologically speaking, identical to physical properties of the body, will be defended in Chapter Three.

It turns out that understanding a difference between Plato and Kant is the key to the resolution of the problem of rationality when viewed as one of the mind-body problems. Before elaborating that difference, however, it will be useful to lay some groundwork by considering the views of two other great rationalists.

An Externalist Account of Intentional Predicates

2010-12-26T11:49:00.000-04:00

Consider Hilary Putnam’s “Twin Earth” argument. Imagine, the argument goes, a Twin Earth: one that is molecule for molecule identical to this Earth. Of course you will have a Twin Earth doppelganger, molecule for molecule identical to yourself. On a reductive materialist account, granting that you have physically identical brain states it follows that you have psychologically identical mental states. For example you will have identical beliefs about water, the colorless, odorless substance that is ubiquitous in your parallel worlds. But imagine that there was just one difference between Earth and Twin Earth: on Earth water is composed of H20, but on Twin Earth water is composed of XYZ. Now everything about you and your doppelganger – both your physical states and your mental contents – are identical, but they’re not the same. Your beliefs may be correct and his/hers false (he/she may believe, as you do, that water is H20), but at a minimum they are about different things. Thus the actual meaning of an intentional state cannot be determined either by its physical properties or, startlingly, by its mental properties (its causal properties that can only be explained with reference to its contents).

Another gedanken from Putnam: Imagine an ant is walking in the sand, behaving normally for an ant for the usual ant reasons. It leaves a trail that resembles a portrait of Winston Churchill. Is this a representation of Winston Churchill? No it is not, even though it has the same physical properties as an actual sketch of Winston Churchill: how it came to be is relevant to its status as a representation. Something is not a representation by virtue of resemblance alone: Winston Churchill, after all, is not a representation of a sketch of himself or of an ant trail that looks like him.

Putnam’s famous slogan is “meaning just ain’t in the head.” The meaning of an intentional state is determined not only by physical and mental properties intrinsic to the subject (“in the subject’s head”) but also by facts about the environment and the subject’s relationship with the environment. This view is called “externalism,” and is also referred to as the “wide content” view: the view that intentional predicates refer to relationships between the nominal subject of intentional predication and their environment.

The representational theory of mind is deeply entrenched and some disambiguation is necessary to avoid outlandish interpretations of externalism and its claims. In this book I am examining the meanings of psychological predicates; in this chapter, intentional predicates. So for me the “meaning” in question is the meaning of words like “believes,” “desires,” “hopes,” “fears” and so on, in the sense of ontological reference: what ontological commitments do we make when we use these words? When Putnam says that “meaning isn’t in the head,” he isn’t talking about the meaning of the word “belief” (my topic), he’s talking about meaning in the sense that the alleged proposition that is the alleged object of the attitude is supposed to be about something: the proposition is the thing that is about something, on the representational realist view, and the proposition is represented “in the head.”

It is a consequence of externalism that beliefs (or any intentional states) aren’t about anything at all. That’s not how they work. They’re not even about the world, let alone internal representations of the world, because what they actually (ontologically speaking) are are relationships between persons and their environments, and relationships aren’t about anything, any more than physical objects or dispositions to behave are about anything. And that is exactly what naturalization requires: that there is no longer any reference to anything that “means” anything, meaning being a non-physical and therefore non-existent “property.” On a functional-role semantics words themselves aren’t about anything, not even proper nouns, so they can’t serve as magical vessels of meaning as they do on a traditional view. Language is a way that persons have of doing things - whole embodied persons situated in particular environments.

Here I am going beyond Putnam (undoubtedly an unwise thing to do!), because Putnam helps himself to mental content even as he argues that mental content alone is not sufficient to determine meaning. But if meaning, understood as “wide content,” turns out to be a description of relationships between persons and environments then there cannot be any mental content. There are no propositions transcendently emanating from Platonic heaven whether or not some person adopts an attitude towards them. There are only specific, concrete instances of states of affairs (I will use “states of affairs” as a more economical way of saying “relationships between persons and their environments;” this is consistent with the more standard use of the phrase as referring to ways the world could be) and goal-directed, token incidents of language-use.

Is Santa Claus a problem? Can’t one be thinking about Santa Claus even though Santa Claus is not part of the environment? No, Santa Claus is not a problem because Santa Claus is a cultural convention and that counts as part of the environment. One is thinking, in the Santa Claus case, not about a mythical character that is actual because mythical characters are not actual. That’s what “mythical” means. As for misrepresentation (as in the case of the five-year-old who believes that Santa Claus is actual), this is something that can only be demonstrated operationally.

What about a person or creature or what have you that exist only in the imagination of one individual? A stranger who appears in a dream, say? Here the right response is to remind ourselves that we are talking about the semantics of intentional predication, not about private experience. In fact the argument is that there can be no public description of private experience; remember Wittgenstein’s beetle-in-the-box. Note that, to the extent that “interpreting representations” is thought of as a process with a phenomenal component (after all, mustn’t there be “something that it’s like” to interpret a representation?), the putative experience of a representation (can one interpret a representation without experiencing it?) cannot be the criterion for proper intersubjective use of the word (see the discussion of phenomenal predicates in Chapter Three).

But surely dreams are evidence of mental representation? Aren’t dreams, in fact, just direct experiences of mental representation? No: although mental processes often involve experiences that seem similar to inspecting representations, remember that there is no explanatory value in literally positing mental representations. They don’t help to explain dreaming any more than they help to explain perceiving, remembering or imagining. In fact they make the model of the mental process considerably more complicated and difficult; a good reason for denying them. Berkeley thought that to clear up the Lockean mess of properties of objects-in-themselves, properties of objects to cause perceptions, and properties of perceptions, either the “mental” or the “external world” had to go. On that point he was right.

A little bit more disambiguation: my intentions here are perhaps deceptively arcane. I am focused on the metaphysics of the mind-body relationship. When I argue that, metaphysically speaking, there are in fact no such things as “mind” or “meaning,” I am arguing that traditional notions of those concepts are currently misleading us in our efforts to understand how the nervous system works. I don’t think any radical change in the way we talk is called for. In fact it is my view that a great deal of our psychological talk is ineliminable, and I think this goes for “mind,” “reference” and “meaning” just as much as for “belief” and “desire” and “beauty” and “justice,” and for the same reasons. If one accepts the present argument against mental representation, it still makes as much sense as it ever did to ask “What are you thinking about?” or “What is that book about?” or “What does that word mean?” The metaphysical question is about the proper semantic analysis of the way that we have always talked; that is nothing like a critique. As Wittgenstein said, “Philosophy changes nothing.” If the present proposal that intentional predicates pick out relationships between embodied persons and their environments is sound then that has always been what we have been doing. Jettisoning realism about mental representations is a substantial matter for cognitive science – I would stress the importance for developing experimental paradigms in brain science – but it’s hard to see how it could have any effect on popular usage of intentional terms.

To summarize, intentional predicates are applied to whole persons in particular environments, not to brains or nervous systems or neural processes or any physical part of persons. Perceiving, imagining, thinking, remembering and so on are the kinds of things that whole persons do. Among these intentional activities is interpreting. Symbols are interpreted by persons, and thus symbols must be located where persons are located: in the world. It follows that language, a symbol system, is a feature of the person’s environment as well: there are no symbols in the head. There is not, ontologically speaking, any such thing as meaning: there are only particular acts of persons negotiating their environments with use of sounds and symbols (and, following the mereological fallacy argument, this will be true of all language use including idle musings, random thoughts etc). The use of the word “meaning” as applied to intentional predication (“What is he thinking about?” “What does she know about gardening?” etc) is partially constituted by facts about the environment (pace Putnam). The natural semantic for intentional predicates is that they refer to relationships between individuals and their environments. If the account given here is persuasive there cannot be any such things as “mental representations.”

Propositional Attitudes

2010-12-20T08:06:00.000-04:00

When Bertrand Russell coined the phrase “propositional attitude” in his 1921 book The Analysis of Mind, he wasn’t thinking of “proposition” in the sense of a piece of language. He was thinking that what was represented was a situation or what would today most likely be called a “state of affairs,” a way the world could be. However several considerations led subsequent philosophers of mind to take a much more literal view of propositions as linguistic entities and as the objects of the attitudes.

Think of a tiger. Alright: now, how many stripes does your imaginary tiger have? Probably your “mental image” of a tiger turned out not to have a specific number of stripes. But a pictorial representation of a tiger would have to. Linguistic (formal) systems can include relevant information and need not contain irrelevant information, an obvious adaptive advantage over isomorphic (pictorial) representation. Formal representation was more congenial to the operationalists (such as computationalists) who wanted to develop functional models of cognition. Then in the late 1950s the linguist Noam Chomsky, critiquing behaviorism, made the enormously influential proposal that formal syntactical structure was “generative”: grammatical forms like “The_is_the_” allowed for multiple inputs and thus indefinitely many (linguistic) representations. Taken to its extreme this argument appears to show that it is necessary for a being to have a formal system for generating propositions to be capable of being in an intentional state at all. Finally the argument that it is propositions that have the property of meaning and that it is propositions that bear logical relations to each other made it seem that a linguistic theory of representation made progress on the mind-body problem.

On my view this is mistaken: the representational model of mind, by definition, locates “mental content” “in the head.” The basic metaphysical problem with the representational model has by now been made clear: “meaning,” what I have been calling the “intentional property” or the “semantic property,” is an irredeemably non-physical “property” that must be washed out of any naturalistic theory of mind. Once one recognizes that intentional predicates are predicated of whole persons – once one sees that positing mental representations necessarily commits the mereological fallacy – the matter is settled. However there is a tight network of arguments and assumptions about intentional states as “propositional attitudes” that will have to be disentangled to the satisfaction of readers who are disposed to defend representations.

The defender of propositional attitudes will start by pointing out that intentional states can only be individuated by virtue of their respective contents. What makes Belief X different from Belief Y is that X is about Paris and Y is about fish. This looks like a block to reduction: to correlate electrochemical activity in the brain, say, with Belief X, we must already be able to specify which belief Belief X is. We don’t have any way of getting from no-content to content (from the non-mental to the mental). This motivates the problem of mental causation: it appears that the content (meaning) of the proposition is what plays the causal role in the production of behavior: when told to proceed to the capital of France he went to Paris because he believed that “Paris is the capital of France.” All the explanation in physical (neurophysiological) terms one could possibly make wouldn’t be explanatory if it didn’t at some point reveal the meaning that is expressed in the proposition, and it doesn’t: “He believes that Paris is the capital of France” is not shorthand for a causal chain of neurophysiological processes.

Donald Davidson famously pointed out a further problem for the development of “psychophysical laws” (as he called them), laws that systematically identified brain processes with particular instances of intentional thought: no one propositional attitude could ever suffice as the discrete cause of a behavior because the causal implication that the propositional attitude has for the acting subject necessarily emerges from the logical relations that that “attitude” has with all of the other intentional states of the subject. Davidson’s phrase for this was “meaning holism,” the view that meaning (in the sense of explanatory psychological predication) is a property of networks of propositional attitudes, not of individual ones. There is not an assortment of individual intentional states in a person’s mind such that one or another might be the proximate cause of behavior; each person has one “intentional state,” the sum of the logically interrelated network of propositional attitudes.

Propositions are the bearers of logical relations with each other. Physical objects and processes, the argument goes, have no logical relations with each other. To believe that the drinking fountain is down the hall is to have the attitude towards the proposition “The drinking fountain is down the hall” that it is true, and to have a desire for water is to have the attitude towards “I have water” that one wants to make that proposition true. The explanatory utility of the intentional predicates – in this case the ability to make an inference from their coincidence that, all other things being equal, the subject will form an intention to walk to the fountain (that is, to make the proposition “I have walked to the fountain” true) – depends on the meaning of the propositions.

Of course making such an inference from the logical relationship between the two propositions also requires that we make a rationality assumption: we must assume about the subject that he, too, will appreciate these logical relations. That is part of the metaphysical “problem of rationality.” I cannot pretend that the distinction between the problem of rationality and the problem of representation is entirely clear-cut, but at this point I need only present a semantic for intentional predicates that locates logical relations out in the world rather than in the head; that will suffice to defeat the argument that mental content is necessary to explain the causal role of intentional states. The further metaphysical problem about the supposed lack of any correlation between the (contingent) physical relationships between states and processes in the body and the (necessary) logical relationships between propositions is dealt with in the discussion of the problem of rationality that is the second half of this chapter.

The terminal station for the line of argument that meaning is an indispensable property (and thus that representations are an ineliminable feature) of intentional explanation is Platonic realism about propositions. On this view, their role as individuators of intentional attitudes and as bearers of logical relations demonstrates that propositions are matter-independent, mind-independent “abstract objects,” ineliminable from ontology. Taking concrete sentences as the “tokens” and propositions as the “types,” the Platonic realist argues that propositions resist a standard nominalist treatment: a “proposition” cannot be simply the name of the set of all of the concrete sentences that express it. The Platonic realist appeals to our intuition that an unexpressed proposition is still a proposition. The fact that propositions can be translated into multiple languages is taken as a demonstration that propositions are not identical to their concrete sentence exemplars.

Wittgenstein proposes an alternative, behaviorist account of language. Wittgenstein’s famous dictum is that meaning is use. The “meaning” of a word, on this view, is whatever the user (speaker or writer) of the word accomplishes by the action of using the word. This alternative to traditional theories of meaning is often called “functional-role semantics.” Wittgenstein rejects the Platonic picture of concepts as essences: the property-in-itself, as distinct from any and all of the concrete exemplars of the property. Language use, he argues, is a type of behavior that reflects a “mode of life,” in the present case the mode of life of human beings. There are no essential meanings (there is no such thing as “meaning” in the traditional sense at all), just patterns of human behavior that can be roughly sorted out on the basis of resemblances and shared histories (these are language “games”). We may gather together statements about “justice” and note that they have similar contexts of use and similar implications for action, just as all of the members of a family can be linked through chains of family resemblance, but that is all. There can be no representation of justice because there is nothing to represent, just as a family of human beings has no “family avatar.” This argument generalizes to all words and their uses, not only those that we think of as naming “concepts.”

If this is right then we are entitled to nominalism about “propositions” after all. A proposition is nothing more than all of the sentence-tokenings of that particular string of symbols. In fact language loses its supposed “interior,” the meaning traditionally supposed to be within or behind the symbol, just as “mind” can now be seen as intelligible patterns of behavior of persons rather than as something “in the head.” Wittgenstein’s vision was to see everything as surface only, both in the case of mind and in the case of language. Psychological description and explanation, understood as an intersubjective discipline limited by the limits of language itself, was necessarily operational.

Now I can sketch out the first natural semantic, the one that replaces intentional predicates that attribute mental representations to persons.

The mereological fallacy

2010-12-12T10:56:00.000-04:00

Stomachs don’t eat lunch. Eating lunch is something that a whole, embodied person does. We understand the role that stomachs play in the lunch-eating process; we appreciate that people can’t eat lunch without them. Brains don’t think. They don’t learn, imagine, solve problems, calculate, dream, remember, hallucinate or perceive. To think that they do is to commit the same fallacy as someone who thought that people can eat lunch because they have little people inside them (stomachs) that eat lunch. This is the mereological fallacy: the fallacy of confusing the part with the whole (or of confusing the function of the part with the telos, or aim, of the whole, as Aristotle, who once again beat us to the crux of the problem, would say).

Nor is the homunculus a useful explanatory device in either case. When I am asked how we might explain the workings of the mind without recourse to mental representations, the reply is that we fail to explain anything at all about the workings of the mind with them. “Remembering my mother’s face is achieved by inspecting a representation of her face in my mind.” This is explanatorily vacuous. And if reference to representations does nothing to explain dreaming, imagining and remembering, it is particularly egregious when mental content is appealed to for an explanation of perception itself, the original “Cartesian” mistake from which all of the other problems derive. A person is constantly developing and revising an idea of his or her world; you can call it a “picture” if you like (a “worldview”), but that is figurative language. A person does not have a picture inside his or her body. Brains don’t form ideas about the world. That’s the kind of thing people do.

This original Cartesian error continues to infest contemporary cognitive science. When the brain areas in the left hemisphere correlated with understanding speech light up and one says, “This is where speech comprehension is occurring,” the mereological fallacy is alive and well. Speech comprehension is not something that occurs inside the body. Persons comprehend speech, and they do it out in the “external” world (the only world there is). Positing representations that exist inside the body is an instance of the mereological fallacy, and it is so necessarily, by virtue of the communicative element that is part of the definition of “representation,” “symbol” etc. Neither any part of the brain nor the brain or nervous system considered as a whole interprets anything. The key to a natural semantic of intentional predicates is the realization that they are predicated of persons, whole embodied beings functioning in relation to a larger environment.

This realization may also be momentous for brain science. Go to the medical school bookstore, find the neurophysiology textbooks and spend a few minutes perusing them. Within the first minutes you will find references to the movement of information (for example by the spinal column), maps (for example on the surface of the cortex), and information processing (for example by the retina and in the visual cortex) and so on. (Actually I suspect that brain scientists are relatively sophisticated in their understanding of the figurative nature of this kind of language compared to workers in other areas of cognitive science; the point is just that representational talk does indeed saturate the professional literature through and through.) But if brain function does not involve representations then we don’t know what brains actually do, and furthermore the representational paradigm is in the way of finding out: the whole project needs to be reconceived. If there is any possibility that this is true at all then these arguments need to be elaborated out as far as they can be.

Taking the argument from the mereological fallacy seriously also draws our attention to the nature of persons. It follows from what has been said that the definition of “person” will be operational. Operational definitions have an inevitably circular character: a person is any being that takes intentional predicates. One might object that we routinely make intentional predications of, say, cars (“My car doesn’t like the cold”), but as Daniel Dennett famously pointed out this objection doesn’t go through when we know that there is a “machine-language” explanation of the object’s behavior: I may not know enough about batteries, starters and so forth to explain my car’s failure to start in the cold, but someone else does, and that’s all I need to know to know that my “intentional” explanation is strictly figurative. But then don’t persons also have machine-language explanations?

No: my car won’t start because the battery is frozen. The mechanic does not commit any fallacy when he says, “Your battery’s the problem.” The part is not confused with the whole. It’s really just the battery. Now suppose that you are driving down the freeway searching for the right exit. You remember that there are some fast-food restaurants there, and you have a feeling that one always thinks that they have gone too far in these situations, so you press on. However you manage to do this, it is no explanation to say that you have done it because your brain remembered the fast-food restaurants, and has beliefs about the phenomenology of being lost on the freeway, and decided to keep going and so forth. That’s like saying that you had lunch because your stomach had lunch.

In fact there is not a machine-language explanation of personhood. Kant, writing in the late 1700s, is fastidious about referring to “all rational beings,” he never says “human beings”; he understands that when we are discussing the property of personhood we are discussing (what I would call) a supervenient functional property (Kant would call personhood “transcendental”), not a contingent physical property. Unfortunately Kant is programmatically intent on limiting the scope of materialism in the first place and thus fails to develop non-reductive materialism. But he understood that the mental cannot be one of the ingredients in the recipe for the mental.

The spectrum of materialisms

2010-12-05T12:51:00.001-04:00

By the 1950s a burgeoning physicalist ideology led philosophers to go beyond the methodological scientism of behaviorism and try to develop an explicitly materialist theory of mind. (I prefer the term “physicalist” to “materialist,” but in this part of the literature the term “materialist” is almost always used so I will follow popular usage.) This movement had everything to do with the intense flowering of technology in this period. For example, electrodes fine enough to penetrate neural axons without destroying them allowed for the measurement and tracking of electrochemical events in live brains. This immediately led to demonstrations of correlations between specific areas of the brain and specific mental abilities and processes. It seemed to be common sense that the materialist program would essentially consist of identifying mental states with physical states (of the brain): “identity theory.”

This is reductive materialism, the view that the descriptive and explanatory language of psychology can be reduced (or translated, or analyzed) into the language of neurophysiology (or maybe just physiology: the argument here does not depend on anyone holding that the brain is the only part of the body that instantiates mental states, although many have held that position. I will continue to use the word “brain” for the sake of exposition). The identity theorists couldn’t say that brain states caused mental states or somehow underlay mental states because that would still distinguish the mental from the physical. The theory had to say that what mental states really were were physical states. Reductive materialism/identity theory is common sense (albeit incorrect) materialism, and stands at the center of the materialist spectrum, with a wing on either side (I have heard philosophers refer to the two wings as the “right wing” and the “left wing,” but I neither understand that categorization nor see how it is useful. One can make arguments to the effect that either wing is the “right” or the “left” one).

The essential metaphysical problem for reductive materialism is not, in retrospect, hard to see: intentional states are multiply realizable, supervenient on their physical exemplars. (A crucial point for the larger argument of this book is that this is a problem for intentional states specifically; the following arguments do not go through for consciousness.) Since the extension of the set of potential subjects of intentional predicates is not fixable with any physical specifications, reductive materialism is “chauvinistic,” as it means to identify a given intentional state (the belief that there are fish in the barrel, say) with some specific human brain state.

Functionalism is a response to this metaphysical problem. Functionalism stresses the type/token distinction: while token-to-token identity is possible, type-to-type identity is not. That is, every token (every actual instance) of an intentional state is instantiated by some specific physical state (assuming physicalism, which technically speaking functionalism doesn’t have to do). Functionalism plus physicalism is non-reductive materialism, one of the wings of the materialist spectrum. Functionalism abstracts away from the token physical instantiations by replacing physical descriptions with functional descriptions. (Aristotle, trying to block the reductive materialism of Democritus, located this block at the level of biological description rather than psychological description, and his ideas continue to be of the utmost importance for philosophy of mind to this day.) A mature functionalist psychology, free of references to the human body, would amount to a generic set of performance specifications for an intelligent being; in this way functionalism (that is cognitive psychology, computer science, logic, robotics and other functional-descriptive pursuits) provides a “top-down” model for backwards-engineering the human nervous system itself, tunneling towards a link with the “bottom-up” (or “wetware”) researches of neurophysiology, evolutionary biology, physical anthropology etc.

Although functionalism is of great use as a heuristic it is not clear that non-reductive materialism, considered as a theory of mind, succeeds in addressing the problem of mental representation, let alone in resolving it. On the non-reductive materialist theory a given mental state, for example the belief that the fish are in the barrel, is defined as any physical state X that plays the appropriate causal role in the production of behavior, as in “Flipper is trying to upend the barrel because Flipper desires fish and X.” This formula usefully allows for the possibility that the relevant function might be achieved without the use of representations, but it doesn’t rule out the use (the existence) of representations. In failing to resolve the problem of the semantic property (or, for that matter, the problem of rationality) in favor of a physicalist semantic functionalism is something less than a full-blown “theory of mind.”

However, functionalism, or I should say the recognition of the problem of multiple realizability that motivates functionalism, does express the central problem for the other wing of the materialist spectrum. On the other side of reductive materialism from non-reductive materialism is eliminative materialism. Eliminative materialism emphasizes the possibility that a mature naturalized psychology need not be expected to provide a physical semantic of intentional states. The eliminativist argues that it is possible that the intentional vocabulary might instead be replaced altogether with a new, physical vocabulary. After all, while Zeus’s thunderbolts have been inter-theoretically reduced to electrical discharges, the heavenly spheres are not identified with anything in our contemporary astronomy. The history of science provides many examples of both reduction and elimination. The research program of cognitive science cannot just assume that the categories of traditional intentional psychology (“folk psychology”) carve the psychological world at its joints. Thus eliminativists propose the “Theory Theory,” the idea that the intentional vocabulary amounts to a particular theory about the mind, and that it is an old vocabulary that might be eliminated rather than reduced.

My uncle Ed, a devotee of corny jokes, likes to tell the one about the tourist who pulls over to ask the local how to get to Hoboken (all of Ed’s jokes are set in his beloved New Jersey). Thinking it over, the local finally says, “You can’t get there from here.” Eliminativism about the intentional vocabulary has a you-can’t-get-there-from-here problem. To say that the intentional vocabulary is subject to elimination is to say that we might talk another way. But as things stand, it can only be said of the eliminativist that they desire to show that we need not necessarily speak of desires, that they believe that “beliefs” are part of an eliminable vocabulary, and so on. For a time I thought that this merely indicated that eliminativism, like functionalism, was something less than a fully realized theory of mind, but the problem is more serious than that and we can see why by considering once again the problem of multiple realizability.

Socrates asks the young men to define justice. They try to explain the property by giving examples of just and unjust actions and of situations where justice does or does not obtain. Socrates rejects this method: examples of justice, he argues, can never be the definition of justice. Plato thinks that supervenient properties are transcendental properties. They do not emerge, somehow, from the contingent physical world (like Aristotle Plato is opposed to reductive materialism). Rather the physical world takes on intelligible form through participation, somehow, with the transcendental (I will return to Plato’s metaphysics in the discussion of the problem of rationality below). The supervenient nature of these properties demonstrates, to Plato’s mind, that they do not come to be and pass away along with their various, impermanent, physical instantiations. Plato was the first philosopher to recognize that intentional predicates supervene on multiple physical things; ultimately his argument is that souls are immortal because properties are immortal.

“Or again, if he (Anaxagoras) tried to account in the same way for my conversing with you, adducing causes such as sound and air and hearing and a thousand others, and never troubled to mention the real reasons, which are that since Athens has thought it better to condemn me, therefore I for my part have thought it better to sit here…these sinews and bones would have been in the neighborhood of Megara or Boeotia long ago” (Phaedo 98d).

Wittgenstein rejected Plato’s search for transcendent essences, but not the ineliminable nature of the intentional predicates. While Wittgenstein thinks that individual, concrete instances of uses of a word (that is, the set of actual tokens of the word) are all there is to the “meaning” of the word (“meaning” is simply use), he identifies psychological predicates with a form of life: “To imagine a language is to imagine a life-form.” Like Aristotle Wittgenstein identifies psyche with life itself, not with the “mind” (towards which he has a Humean skepticism).

In sum, what the multiple-realizability (the supervenient nature) of intentional predicates demonstrates is that they cannot be replaced with some other way of talking. We can no more dispense with “belief” or “desire” than we can with “beauty” or “justice.” These words simply do not refer to any finite, specifiable set of physical characteristics of any finite, specifiable set of physical things. At a minimum this strongly suggests that the intentional vocabulary is ineliminable. (Again, none of this holds for phenomenal predicates. They require a completely different treatment that they will get in Chapter Three.) It follows from this that intentional predicates do not refer to any “internal” states at all, which is the key to developing a natural semantic for them.

First, though, let’s finish the discussion of eliminative materialism. There are two types of eliminativism. The first is the kind I have been discussing, the kind usually associated with the name: eliminativism about intentional predicates. But we have seen that physical analysis of nervous systems has no greater prospect of eliminating intentional predicates than physical analysis of works of art does of eliminating aesthetic predicates. What physicalism does both promise and require is the elimination of any reference to clearly non-physical properties (supervenient properties are not “clearly non-physical”; what their metaphysical status is continues to be the question that we are asking).

No, the clearly non-physical property in which intentional predication allegedly involves us has been clear all along: the semantic property. The only eliminativism worthy of that mouthful of a name is content eliminativism. As Jerry Fodor has written, “I suppose that sooner or later the physicists will complete the catalogue they’ve been compiling of the ultimate and irreducible properties of things. When they do, the likes of spin, charm, and charge will perhaps appear on their list. But aboutness surely won’t; intentionality simply doesn’t go that deep.” Representation is the only game that we know is not in town (although some further discussion of Fodor, one of the most important contemporary writers on this topic and a champion of the representational theory, will be necessary below). How ironic, then, that some of the philosophers most closely associated with “eliminative materialism” are in fact very much wedded to the representational paradigm when mental representation is the one and only thing that physicalism has to eliminate in order to be physicalism at all.

The modern history of representation

2010-11-28T15:03:00.000-04:00

So internalized is the representational view that one can forget that it didn’t have to be this way. The history of psychology is, like all histories, full of contingencies and precipitous forks in the road. In the study of the history of Western philosophy we call the 17th and 18th centuries the “Early Modern” period, and the contemporary idea that we live in our heads, experiencing only a mental representation of the world, dates from this period. It was an incredibly fertile period for European philosophy: if we take, as most do, Descartes to be the first canonical Early Modern philosopher and Kant to be the last, the whole period is a scant 154 years (from the publication of The Discourse on Method in 1637 to the publication of The Critique of Pure Reason in 1781).

The adjective “Cartesian” literally means that an argument or position reflects the ideas of Descartes, but it has become through usage a more general term that alludes to representational theories of mind, particularly those theories that entail that we must worry about the relationship between the external world and a perceiving subject’s representation of the world – theories that “explain” perception as the formation of representations. This is not entirely fair to Descartes, who wrote in his Dioptics that it would be a mistake to take the inverted image observable on the retina as evidence that there were pictures in the mind, “as if there were yet other eyes in our brain.”

Even if the real Descartes was not someone who today we would call a Cartesian, he can certainly be held responsible in large part for the conspicuous lack of naturalism about psychology in modern philosophy: he was a metaphysical dualist, he thought that humans’ rational capacity comes not from nature but from God (notoriously he made this argument after arguing that he could prove God’s existence through the exercise of rationality), and he was a human exceptionalist who took language as evidence that humans are essentially different from the rest of the natural world. But the real “Cartesian” in the sense of the true ancestor of modern representational theory is Kant.

Kant’s explicit project was to block the naturalization of psychology. He was alarmed by what he saw as the atheistic, amoralist implications of Hume’s empiricism (implications emphasized by Hume himself). Hume’s whole oeuvre can be read as a sustained attack on the very idea of rationality: there are no “rational” proofs of anything, no “rational” reason for believing in anything. Beliefs are the product of “habituation,” the conditioning effect of regularities of experience. Thus there was no basis, on Hume’s view, for asserting the existence of God, of human freedom, or even of the human mind if by that was meant something over and above the contents (the “impressions”) of thought processes, which were the products of experience. Kant seems to have been intuitively certain that these radical conclusions were false, although he was criticized (by Nietzsche for example) for a programmatic development of foreordained conclusions.

Hume’s psychology was inadequate. Like Locke before him he thought that mental content could be naturalized if it was explained as the result of a physical process of perception: interaction with the environment was the physical cause of the impression, a physical effect. This strategy led the empiricists to emphasize a rejection of innate content, which they regarded as a bit of bad rationalist metaphysics. The problem was compounded by a failure to distinguish between innate content and innate cognitive ability. To some extent this failure reflected a desire to strip psychology down to the simplest perception/learning theory possible in the interest of scientific method, coupled with a lack of Darwinian ideas that can provide naturalistic explanations of innate traits (I will address the skeptical, “phenomenalist” reading of Hume, that I think is incorrect, in Chapter Three).

Kant saw this weakness and was inspired to develop the argument of the Critique of Pure Reason. Hume claimed that all knowledge was the result of experience. Kant’s reply was to ask, “What is necessary in order for experience to be possible?” The greatness of Kant is in his effort to backwards-engineer the mind. He is best read today as a cognitive scientist. However people forget how radical Kant’s conclusions were, and how influential they have continued to be, one way or another, to virtually all philosophers and psychologists since the late 18th century. From the persuasive argument that the mind must somehow sort and organize the perceptual input (that’s the part of psychology that the empiricists’ ideology led them to neglect), Kant goes on to argue that space, time, cause and effect relations and the multiplicity of objects are all part of the “sensible” frame that the mind imposes on our experience of the world. The world of our experience is the phenomenal world, and it is that world that is the subject of natural science; the world-in-itself is the noumenal world (and quite the bizarre, Parmenidean world it is!).

Two points are important here. First, Kant’s aim was to protect human psychology (and religion and ethics) from a godless, amoral, reductive natural science and in that he succeeded to an alarming extent. The world of natural science on the Kantian view is the world as it is conceived by the rational mind, and as such the rational mind itself cannot be contained in it. Second, Kant’s biggest contribution of all is easy to miss precisely because it is so basic to his whole line of argument: the phenomenal world is a representation, made possible by the framing structure of rational conception, just as the drawing on the Etch-a-Sketch depends on the plastic case, the internal mechanism and the knobs of the toy.

The defender of Kant will argue that the Kantian phenomenal world is not a representation at all: it is the world presented to us in a certain way. It is also only fair to point out that Kant, unlike his modern descendents, shared with Plato the view that all rational minds were identical to the extent that they were rational. Kant would not have been amused by 20th century philosophers’ pictures of a world where each language, culture and individual were straying off, like bits some expanding universe, into their private “conceptual schemes,” ne’er the twain to meet. Nonetheless Kant needs mental representation (and any conceptual schemata is representational), because he needs to protect freedom, rationality, God and ethics. Thus a deep skepticism is intentionally built in to Kant’s system (as it is not in Descartes’). While Kant is right in a great many things and any student of philosophy or psychology must read and understand him, on these two points his influence is ultimately pernicious.

I dilate on the Kantian history of the representational theory because once we see that the issues that confront us in philosophy of mind continue to be essentially metaphysical we also see that they are very old issues, and ones that connect up with many other perennial philosophical problems. Too many people in contemporary philosophy of mind and cognitive science fail to appreciate this and the discussion is very much the poorer for that. Furthermore it’s important to see that things didn’t have to be this way. The idea that we are stuck in our heads with our “representation” of the world forever mediating between us and “reality” is actually a very strange idea, but it has been so deeply internalized by so many that we can fail to appreciate how strange it is. This is something to bear in mind as we think about how modern physicalist philosophy of mind has struggled with the problem of mental representation.

The Problem of Mental Representation

2010-11-14T13:00:00.000-04:00

People tend to be of two minds (pun intended) on the issue of mental content. On the one hand no one can dispute that the way we talk about the mind is largely figurative. The mind is racing and wandering, it has things on it and in it, it is sometimes full and sometimes empty, it is open and narrow and dirty and right. We are used to talking this way, it is useful to talk this way (I don’t think there is anything wrong with our psychological talk), and everybody pretty much understands that this is a discourse full of “figures of speech.” The philosophically-inclined see well enough that “mind” is an abstract concept of some sort. On the other hand we have deeply internalized some of this figurative language, so deeply that one of the most central, perennial problems of epistemology is the alleged problem about the relation of our “inner” perceptions of the world to the “real world” out there, outside of our heads. Many people think that we are stuck inside our heads: a blatant conflation of the literal with the figurative.

Why is this? For one thing when we talk about the mental we must use the language that we have, and this is a language evolved for talking about the physical, “external” world of three-dimensional objects in three-dimensional space. The room has an inside and an outside, and there are things (concrete things) inside it (those chairs and tables that philosophers are always talking about). “Beliefs” and “sensations” are words that take the same noun-role as “chairs” and “tables,” and thus the grammar of the language is constantly pushing us to conceive of these mental terms as referring to some variety of concrete things. This is the sense in which Wittgenstein uses the word “grammar”: to indicate the way that language contains metaphysical suggestions that can lead to confusion. The metaphysical grammar of language is the grammar of three-dimensional objects in three-dimensional space; objects, moreover, that interact with each other according to regularities of cause and effect.

A basic confusion about the mind is that it is a kind of inner space filled with things and (non-physical) processes. It is important to see the close relationship between this pseudo-spatial conception of the mind and the problem of mental representation. Physical things and processes don’t mean anything (or, physical descriptions and explanations of the things and processes in the world don’t refer to the semantic property, only to physical properties). The concept of a symbol is essentially relational: symbols need to be interpreted. For interpretation to happen there must be an interpreter. Pictures, books and computer screens need to be looked at by someone – someone with a mind. Thus the representational model has a “homunculus” problem: in order for the symbol to work it must be read by someone, as streetlights and recipes only “work” when actual people respond to them with appropriate actions. Another way of putting the problem is the “regress” objection: if the theory is that minds work using representations, then the homunculus’s mind must work that way as well, but in that case the homunculus’s mind must contain another homunculus, and so on.

Some cognitive scientists have tried to overcome this objection by suggesting that a larger neural system of cognition can be modeled as responding to information from neural subsystems without succumbing to the homunculus fallacy, but this strategy can’t work if a “representational” theory of mind is one that posits representations as necessary for thought. A theory of mind that succeeds in naturalizing psychology will be one that shows how the “mental” emerges from the non-mental. Any theory that includes anything mental in the first place accomplishes nothing. The concept of a representation is a mental concept by definition: the verb “to represent” presumes the existence of an audience. Representation, like language, cannot be a necessary precondition for thought for the simple enough reason that thought is a necessary precondition for both representation and language (a being without thoughts would have precious little to talk about!). This is not a chicken-and-the-egg question.

There is an important discussion here with the computationalists, who think that the mind/brain is a kind of computer. If it is the representations that bear logical relations to one another (the computationalist argues), and rationality consists in understanding and respecting those relations, then rationality requires a representational (typically thought of as some sort of linguistic) architecture. If computation is formal rule-governed symbol manipulation then symbols are necessary for computation/cognition. Jerry Fodor, for example, hopes to bridge mind (intentional explanation) and body (physical explanation) by way of syntax, the formal organization of language. The idea is that all of the causal work that would normally be attributed to the content of the representation (say, the desire for water) can be explained instead by appeal to “formal” (syntactic, algorithmic) features of the representation (there is some more discussion of Fodor below).

One challenge to this computationalist (or “strong AI”) view is connectionism, the view that the mind/brain has an architecture more like a connectionist computer (also called parallel distributed processing, PDP; in the wetware literature this is the “neural nets” discussion). In connectionist computing, systems of nodes stimulate each other with electrical connections. There is an input layer where nodes are activated by operators or sensors, programming layers where patterns from the input layer can be used to refine the output, and the output layer of nodes. These connections can be “weighted” by programmers to steer the machine in the right direction. Some of these systems were developed by the military to train sonar systems to recognize underwater mines, for example, but they are now ubiquitous as the face-, handwriting- and voice-recognition programs used in daily life.

Connectionist machines are very interesting for purposes of the present discussion. They appear to be self-teaching, and they appear to function without anything that functions as a symbol. There is still the (human) programmer and there is still nothing that seems like real consciousness, but such a system attached to a set of utilities (so far, the utilities of the programmers) looks to be effective at producing organized behavior and fully explicable in operational terms.

Meanwhile, I’m not even sure that computers have representations in the first place. That is, it’s hard to see anything that functions as a representation for the computer (which is not surprising since it doesn’t look like the computer has a point of view). What makes computers interesting to cognitive science in the first place is that with them we can tell the whole causal story without appeal to representations: the binary code just symbolizes (to us) the machine state (the status of gates in the microprocessors), and we can sustain the machine-level explanation through the description of the programming languages and the outputs. Those “outputs,” of course, are words and images interpreted by humans (mostly). So even “classical” computers do have computational properties and do not have representations. Or perhaps another way to put it is that two senses of “representation” are confuted here: the sense when a human observes a computational process and explains it by saying: “See, that functions as a representation in that process” and the sense when a human claims to interpret a representation. (I will discuss computational properties as “formal” properties in the discussion of the problem of rationality below.)

The computationalist/connectionist discussion is a striking example of how little the larger discussion has changed since the 17th century. It is the rationalist/empiricist, nativist/behaviorist argument rehearsing itself yet again through the development of this technology.

The Problem of Intentionality

2010-11-07T20:32:00.000-04:00

In the last chapter I argued that there is no one thing to which the word “mind” refers. I argued further that there are (at least) two metaphysical problems that are still unresolved in our psychological talk; two kinds of putative mental “properties” that each, in their respective ways, resists naturalization. It may be, though, that spelling out the heterogeneity of mind is progress: for much of the dissatisfaction with operationalist theories is because of their manifest failure to give a satisfactory account of consciousness, while any straightforward materialist account of consciousness appears to run afoul of the issue of “multiple realizability” and “chauvinism.” Once we accept that we have two different topics it may turn out that our current theories are not as inadequate as they seemed; they are only more limited in their scope than we had assumed.

If this is right then one who is interested in the problem of intentionality needn’t necessarily be interested in the problem of consciousness or vice versa. What appeared to be a fairly violent doctrinal schism between the operationalists and the phenomenologists is revealed to be a mere changing of the subject. Of course if a naturalistic semantic of intelligence-predicates and a naturalistic semantic of consciousness-predicates are both necessary but neither sufficient for a complete naturalistic semantic of psychological predicates, then analyses of both semantics will have to be offered. But each semantic and its defense should be free-standing if the heterogeneity argument in the last chapter is true.

The problem of intentionality itself decomposes further into two interrelated but distinguishable problems. The first is the problem of mental representation. Symbols of any kind (including isomorphic representations like paintings and photographs and formal representations like spoken languages and computer codes) have, it seems, the property of meaning (that I will usually call the semantic property or, interchangeably, the intentional property). Symbols refer to, are about, things other than themselves (the neologism “aboutness” also expresses this property), while physical things (or things described and explained in physical terms) do not have any such property (the descriptions and explanations include only physical terms). A naturalized semantic of psychological predicates would be free of reference to non-physical properties, but even our current neurophysiology textbooks have information-processing models of nervous system function (and the popular conception of the mind is of something full of images, information and language).

The operationalist theories of mind developed by English-speaking philosophers during the 20th century are largely a response to the problem of representation, although there are a variety of conclusions: behaviorism is straightforwardly eliminativist about mental content, limiting the possible criteria for use of psychological predicates to intersubjectively observable things. Computationalism, insofar as it holds that minds are formal rule-governed symbol-manipulating systems, aims at radically minimizing the symbol system (as in binary-code machine language for example) but remains essentially committed to some sort of symbolic architecture. Functionalism proposes a psychology that is described purely in functional terms rather than physical terms, which provides for replacing representations with functionally equivalent, non-representational states, but in its very abstraction functionalism does not commit to eliminating representations (functionalism may be more of a method than a theory). In the first half of this chapter I will draw on the work of some latter-day philosophers, generally influenced by Wittgenstein, to develop a semantic of intentional predicates that not only dispenses with any references to mental representation (as behaviorism and functionalism do) but provides an account that actually rules out the possibility of mental content.

The other part of the problem of intentionality is the problem of rationality. Rationality is multiply realizable (a synonymous term is supervenient). To see what this means consider an example from another area of philosophy, “value theory” (an area that encompasses aesthetics and ethics): Say I have a painting hanging on the wall at home. This painting has a physical description, which lists all and only its physical properties: it is two feet across and four feet tall, weighs seven pounds, is made of wood, canvas and oils, is mostly red etc. Rarely, though, does anyone find these physical properties remarkable qua physical properties. Instead my visitors are likely to remark that the painting is beautiful, finely wrought, significant etc. The metaphysical problem is that these aesthetic properties cannot be analyzed into, reduced to or identified with the painting’s particular set of physical properties (notwithstanding the fact that my visitors will appeal to these physical characteristics, as in “That red tone is lovely,” when elaborating on their aesthetic judgment). The aesthetic properties surely emerge, somehow, from this particular combination of physical properties. There could be no change of the physical properties without some change in the aesthetic properties (this is the standard definition of the “supervenient” relationship). But not all objects with these physical properties are necessarily beautiful, nor do all beautiful things have these physical properties.

Rationality is a supervenient property. For example a human being, a dolphin, a (theoretically possible) rational artifact and a (probably existing) intelligent extraterrestrial all instantiate (that is, grasp and make use of) the function of transitivity (“If X then Y, if Y then Z, therefore if X then Z”). But these beings are made of various materials organized in various ways. There are no physical properties that fix the extension of the set of rational beings and so this set, like the set of beautiful things, is indefinitely large. Another way of saying the same thing is to say that there are no psychophysical laws regarding rationality, generalizations to the effect that any being with such-and-such logical capacity must have such-and-such physical characteristics or vice versa.

The problem of mental representation and the problem of rationality can be distinguished as separate metaphysical problems. We would still be confronted with the problem of rationality even if we did not subscribe (that is, if none of us subscribed) to a representational theory of mind. Nonetheless the two sub-problems should be grouped together under the general rubric of the problem of intentionality, because both are problems for the same set of psychological predicates, the intentional predicates: “believes,” “desires,” “hopes,” “fears” etc. Intentional predicates name states that apparently entail mental content, as one believes that X, fears that Y etc., and also apparently entail rationality, as it is only explanatory when I say to you of a person that he left the room because he was thirsty if we share the background assumption that, if he believes that there is water at the fountain and desires to have water then, all other things being equal, he will go to the fountain (this is commonly referred to as the rationality assumption).

Some philosophers will claim at this point that the necessity of the rationality assumption for intentional explanation blocks naturalization. The argument is that it is the propositions (“I have water to drink,” “There is water at the fountain down the hall”) that bear logical relations to one another. If these propositions are not identical to their various physical tokens then they are non-physical entities (this kind of view is often called “Platonic realism,” that is realism about non-physical entities). This argument also counts against my claim that the two problems of intentionality can be separated if it turns out that tokens of propositions are necessary for logical thinking.

A related worry that also apparently ties the two problems of intentionality together is about the causal role of content (“the problem of mental causation”): The man is running because he wants to get away from the tiger that is chasing him. If a physical description of his brain and the processes occurring there does not convey that he is being chased by a tiger, not only does it fail to provide the kind of explanation we want (we want to know the reason he is running), it also appears to fail to describe what is happening “in his own head,” since the perception of an attacking tiger is part of the cause of his action.

I think that I can provide a satisfactory response to the problem of propositions as bearers of logical relations, although the result is somewhat surprising in the context of the overall physicalist project of this book. However the problem of mental representation will be discussed first, because it is important to see that even if we were to reject the representational theory of mind (as I think we should) we would still be confronted with the problem of rationality. The question of rationality takes us a good deal further into general metaphysics.

Part one of four of discussion of Phaedo 93a-94e

2010-10-31T13:48:00.000-04:00

Part two of four of discussion of Phaedo 93a-94e

2010-10-31T13:46:00.000-04:00

Part three of four of discussion of Phaedo 93a-94e

2010-10-31T13:45:00.000-04:00

Part four of four of discussion of Phaedo 93a-94e

2010-10-31T13:41:00.002-04:00

The Heterogeneity of Mind

2010-10-24T15:32:00.000-04:00

In 1949 Gilbert Ryle published The Concept of Mind, one of the most important books of philosophy of mind of the last century and probably the best manifesto of philosophical behaviorism. Although today few would endorse Ryle’s strictly behaviorist semantics of psychological predicates the book continues to be persuasive as a sustained attack on what Ryle calls “Cartesian” theories of mind. Specifically Ryle challenges the ancient intuition that the word “mind” refers to some one, unanalyzable thing. He does this more thoroughly (and in a grander style) than anything I can do here, but he wrote at a time when the practice of metaphysics was out of favor in the English-language philosophical world. Today we enjoy the benefits of the “language” philosophy that was done by the early 20th century empiricists and the benefits of the revival of metaphysics, which has been to some extent motivated by the emphasis on philosophy of mind, of the past several decades.

Imagine, Ryle asks, that a visitor has asked to be shown the university. One walks the visitor through campus: “There is the Student Center, and there is College Hall, and those young people sitting around the fountain over there are students, and there is old Professor Whiskers, you can set your watch by his walks across campus, and say hello to my friend Imelda here, she’s our new dean, now come I’ll show you the library,” and so on. At the end of the day the visitor is asked what he thought of the university. “But,” he protests, “You didn’t show me the university. We only saw buildings, people, books and things like that.” Ryle argues that a similar “category mistake” is made when we posit, behind or above or in addition to specific, observable behaviors, a “ghost in the machine,” a “mind.” He further argues, echoing Hume, that there is no “inner mental space” where mental events occur. His very title, “the concept of mind,” telegraphs his view that “mind” is a heterogeneous concept.

A heterogeneous concept is one that turns out, under analysis, to consist of multiple, distinguishable things. Ryle points out that the grammatical behavior of nouns is such that we can be led to think that there is something that exists when there is nothing (Dickens’s Mr. Pickwick, for example), but that this is practically speaking the same thing as thinking that only one thing exists when in fact the concept involves many things (Dickens, one of his novels, the tradition of fiction; football players, uniforms, equipment). All I mean by "analysis," that I am not using in any sort of technical manner, is thinking about the referents of the term (semantics and metaphysics often come to the same thing). Examples of heterogeneous concepts from outside of philosophy of mind are value terms like "ethics" or "beauty," or for that matter very many abstract nouns such as (opening the dictionary randomly) "reservoir." Wittgenstein famously explained the heterogeneous nature of the concept of “game.”

Heterogeneous words are common (really, I don’t like to use the word "concept," although it is hard to avoid. It comes with a treacherous load of academic baggage. I'm thinking about the uses of the word; the nature of the “concept” is what is at stake, after all). We can understand the continuity of meaning between "That man's reservoir of good will" and "The city's reservoir of water" (the first use started as a simile of the second) but if we are thinking about what the word refers to the two uses are different enough that it makes most sense to say "'Reservoir' is a heterogeneous word," meaning that it is a word that can refer to multiple, distinguishable things.

If we stay alert to the fact that individual nouns, and particularly abstract nouns, routinely turn out to refer to distinguishable things we can sometimes clear the smoke away a bit from philosophical arguments. For example ethical theorists (perhaps not the best ethical theorists, but quite a few ethical theorists) might see themselves as involved in some sort of partisan contest: are the “rights theorists” correct (or better or what have you), or are the “consequentialists” the ones who are giving us the best account of things? Or maybe virtue theory is preferable to both? Certainly philosophers working on ethical theory are frequently identified as “rights theorists” or as “consequentialists”: “I’m a consequentialist” is taken to mean not only that one endorses consequentialism but also that one declines to endorse the other types of ethical theory on offer.

But wait: actual people are "ethical" on a formal, logical sort of level (respecting others' rights through applying the logic of universality) and "ethical" on a situational, emotional sort of level (minimizing felt harm through the capacity for empathy) and they appreciate "good" people who they estimate to be salutary examples of a well-realized person (a “gentleman of Athens”). In fact real ethical people (that is, people when they're actually trying to act ethically rather than merely trying to do ethical theory) use Kantian-style "golden rule" reasoning and Millian outcomes-oriented strategies and they make Aristotelean evaluations of themselves and others all at the same time. “Ethics" turns out to be a heterogeneous concept: the intentions of rational beings, the qualitative experiences of conscious beings and the health or pathology of living beings are all different things, such that there turn out to be not so much differences of opinion among "ethical theorists" as there are changings of the subject. Confusion (and sound and fury) is generated by a presumption that ethical thinking must be one kind of thinking and so there must be one “theory” that gives an account of it. The misleading grammar in this case is the use of a singular abstract noun “ethics,” which creates the strong impression that there is only one topic when in fact there are several that come under that rubric.

The alarmed ethical theorist might speak up at this point: “Too fast.” When David Hume says “Reason is the slave of the passions,” he is making the substantial claim that logical operations are secondary and merely instrumental and that qualitative experience is the primary explanans of “ethics.” When Kant argues that all and only rational beings constitute a “kingdom of ends” he is making a substantial claim that the physical universe portrayed by science (the “phenomenal world”) is valueless qua physical, and that transcendental logical necessity is that explanans. These look to be mutually exclusive claims, and neither is compatible with Aristotle’s view that fulfilling the telos of a living human being is ultimately the aim of “ethical” behavior.

And mutually exclusive they are. But the claim that experience is the only thing we know, or the claim that there are no values in the physical world studied by science and that therefore they must come from somewhere else, are metaphysical and epistemological claims. All philosophy is about metaphysics and epistemology, as unfashionable as it may be to say so these days. And Hume (about whom I will have a good deal more to say in Chapter Three) points out the curious fact that no amount of discussion of physical experience produces any account of programmatic duty, while Kant is moved by his sense of the amorality of the physical world to make the radical claim that the phenomenal world is not, could not be, all that there is. The penultimate difference between Hume and Kant is a difference about the nature of the human mind; like all of the best philosophers their views on both ethics and psychology are systematically motivated by more central positions on epistemology and metaphysics. So if there is a persuasive argument that mind is a heterogeneous concept that argument will extend to the claim that ethics is a heterogeneous concept.

The deeply-internalized intuition that there is some one thing that is the “mind” reflects the plain fact that there is one thing that is the body. For each person the body is singular (at least in our experience!), and once the idea emerged that the mind existed separately from the body (or, at least, that the mind was metaphysically distinct from the body) it was natural to think that there was a one-to-one correspondence between bodies and minds (or “souls”). But the burden of proof is surely on those who would maintain that psychological predicates refer to some one, unanalyzable thing. The metaphysical dualist points to the difficulty we have in providing a naturalistic semantics for psychological terms as a justification for accepting dualism, but we have already seen that the intentional terms and the phenomenal terms resist naturalization in different ways: we might eventually be forced to accept a dualist account of the intentional mind but not of the phenomenal mind, or vice versa, so even a convincing argument for dualism wouldn’t entail that psychological predicates refer to something homogeneous.

As for phenomenal arguments about the unity of perception, apperception, consciousness or what have you, “unity” is exactly what one would expect if one held that in the final analysis psychological predicates referred to embodied beings in physical environments. Kant, one of the greatest and richest philosophers in this field, has to work hard on his account of the unity of mind because he does endorse just the distinction between the rational mind and the conscious (that is physical-world-experiencing) mind that I am stressing here, he doesn’t think that the rational mind can be naturalized and he does think (he fears) that the conscious mind can be. (Strictly speaking Kant’s famous distinction between the “noumenal” and the “phenomenal” worlds is epistemological – the world of experience is that part of the world-in-itself that our minds can feature in a representation – but if rationality is assigned to the noumenal and sensory experience is assigned to the phenomenal then the distinction is equivalent to the one I am making here.) If there were persuasive natural semantics available for both types of psychological predicate (contra Kant who thinks there can be none for intentional predicates) then the “unity of mind” would have been shown to be simply the unity of body: to claim that mind is unanalyzable prima facie is to beg this question.

There is one more objection that cannot be avoided, this one from familiar arguments in the area of personal identity. A defining argument in the area of personal identity is that between advocates of physical continuity and advocates of psychological continuity. At least since the time of Locke the majority view has been that psychological theories of personal identity are more persuasive than physical theories. Imagine (the story goes) that one’s mind has been switched with another (physical) person’s: mind A in body B and mind B in body A. Where (one asks the students) are you now? Most people have the intuition that they go where their mind goes, that is, that they are their mind as opposed to their body if forced to make the choice. It is significant that it does seem possible to conceive of one’s mind separated from one’s body. Isn’t that a problem for any physicalist theory of mind? I think it is, and I will take up the issue of what it is actually possible to conceive, and what that possibility might show, in Chapter Three in the discussion of the “absent qualia” arguments, the possibility of “zombies” etc.

But what is at issue in this section is not the mind/body problem itself but the ground-preparing question of whether there are two problems rather than one. Consider the “memory theory” owed to Locke himself. On this view shared memories are the psychological link that establishes the continuity of self across the passage of time (the old general remembers the brave officer’s battle, the brave officer remembers the young boy stealing the apple and so forth). But if the operationalist holds that memory is a representational system that gains, edits and stores information, this functional ability is not sufficient to constitute selfhood: two beings with the same database are not thereby the same person. And if the phenomenologist is right that no amount of functional description will ever capture the quality of conscious experience then there can be no purely functional account of memory itself, let alone of personal identity.

If, on the other hand, we have a phenomenal account of memory continuity – that would have to be something like “having memories with the identical qualities” – then we get the problem in reverse, since we cannot establish the causal role of consciousness (which is just another way of putting the phenomenologist’s point that we cannot provide a functional account of consciousness). So a phenomenal account of memory (whatever that might be) would also not be sufficient if used to try to establish personal identity. Identity of representational content and identity of qualitative experience are both necessary, but neither is sufficient, for personal identity. Since the reason that neither account of memory is sufficient is that each leaves the other one out that establishes that they are two different things.

To summarize, my claim is that there are two metaphysical problems for the naturalization of psychology. My method is to look at the metaphysical commitments – the semantics – of the vocabulary of psychological predication. This vocabulary divides into two sets of words. First there is the intentional vocabulary. This consists of words like “belief,” “desire,” “hope,” “fear” and so on. Use of these words appears to commit us to the existence of rationality and mental representation; I will use the word intelligence to refer to the intentional mind in toto. The other set is the phenomenal vocabulary. This consists of words like “sensation,” “pain,” “taste,” “texture” and so on. Use of these words appears to commit us to the existence of consciousness. Operationalist theories are theories about intelligence; phenomenal theories (which are rather thin on the ground, for reasons I will discuss in Chapter Three) are theories about consciousness.

Once one sees that there are two mind/body problems, not one, it is possible to address each problem in turn. Chapter Two breaks down the problem of intentionality further, developing the distinction between the problem of mental representation and the problem of rationality, and offers two respective arguments to naturalize the semantics of intentional predicates. Chapter Three offers arguments to the effect that the problem of phenomenology is a pseudoproblem and then explains how phenomenal predicates can be naturalized as well. The arguments in the two chapters are different responses to different metaphysical problems, but taken together they may work towards a naturalistic semantic for psychological predicates. In the more speculative Chapter Four an account of the nature of the relationship between intelligence and consciousness is proposed that reflects the conclusions of the earlier chapters.

Consciousness: the other horn of the dilemma in philosophy of mind

2010-10-17T12:14:00.001-04:00

I take Turing’s thought experiment to be entirely persuasive, with the radical and happy outcome that, among other things, it reveals the old epistemological chestnut “the problem of other minds” to be a pseudoproblem (Wittgenstein emphasizes this). There is another famous gedanken-style argument in the philosophy of mind that I find equally persuasive, owing to John Searle: the Chinese Room Argument. I found both the Turing Test and the Chinese Room Argument to be rather fast and baffling at first, and then I went through a period of doubt and resistance, but I cannot find any argument that shows either of them to be fallacious or misapplied (and many, many have tried). I now feel certain that they are both correct. The only problem is that they are mutually contradictory.

Imagine, Searle asks, a person in a room. The room has a slot where people outside the room can enter printed notes and another slot where he can put out notes in response. This person cannot read or speak Chinese. He has two things: a large cache of Chinese characters (maybe he has a Chinese-character typewriter), and a set of instructions. The instructions are purely formal: for each Chinese character or set of characters that comes in to the room, there is specified a character or set of characters to be put out. Chinese-speakers write notes and put them into the room: “What is the capital of France?” say, or “What is your favorite food? Mine is chocolate.” or “I plan to vote for Obama, but my brother disagrees.” The person in the Chinese Room examines the characters, finds them in the instruction manual, and prints out the responding characters that are specified there. The instructions are such that the Chinese-speakers are satisfied that they are conversing with an intelligent being, one that knows something about geography and any number of other topics and can converse about food, politics, relatives and so on.

According to Turing, the Chinese-speakers (and everyone else outside the room) would have to conclude that the Chinese Room was intelligent. In fact the Chinese Room just is intelligent (no inference is necessary) since, on the operationalist view, “intelligence” consists of nothing more nor less than this kind of intelligent behavior; there is no question of being wrong here. On the contrary, Searle argues that the Chinese Room knows nothing. Neither the person in the Room nor the Room as a whole has any idea what the topic is, or even that there is a topic: not even that the characters mean anything at all. The Chinese Room is, according to Searle, a formal rule-governed symbol-manipulating device and nothing more, and as such it knows nothing at all, and nothing that knows nothing can be considered “intelligent.” A thing lacking all awareness is not an intelligent thing.

Searle’s specific target is computationalism, the view that (human) cognition is a form of computation, in other words that intelligent humans are formal rule-governed symbol-manipulating systems. He doesn’t think that an intelligent artifact is impossible, because he’s a materialist: he accepts that an artifact with the same relevant causal properties as a human body would have the same kind of intelligence. It’s just that a computer is not that artifact. A computer can have a data-base as full of symbolic representations (words, pictures) about Paris as you like, but it is only the human user who can grasp what the symbols represent. And what is that? Cheese shops full of hard parmesan and soft camembert, well-dressed people whizzing by on motor scooters, cigarette butts stuck in the metal grid floors of the Metro: a specific place full of sounds, smells, textures, tastes and scenes.

The taste of the wine, the smell of the cigarettes, the feeling that the well-dressed people don’t admire your ensemble: these are conscious experiences. Humans have them, computers do not. Only beings who have conscious experiences (who are, that is, conscious) can know what a symbol stands for, because “knowing” consists of an appreciation of the quality of the relevant experiences. A human doesn’t even have to have been to Paris to get some feel for the place; they can read about it on their computer screen! No amount of increase in the computational power of a mere formal rule-governed symbol-manipulating device will be sufficient for understanding absent this capacity for qualitative experience. This capacity is consciousness.

But how is it that consciousness is a metaphysical problem? Here is another famous gedanken-style argument, this one owed to Frank Jackson, which makes the metaphysical nature of the problem clear. Imagine Mary, a color-blind color-vision specialist. Mary is an expert on the science of color perception. This involves a great deal of scientific expertise: Mary knows about the physics of light, for example about how red light has a spiky amplitude and blue light a flat one; she knows about the light-absorbent and –reflective properties of surfaces; she understands the way the rods and cones on the back of the retina measure the amplitude of light and accordingly stimulate the optic nerve; she knows about the visual cortex and how the cells are arranged and connected there. Let’s say Mary is the world’s foremost color-vision specialist. Let’s even idealize Mary a little bit: let’s say that she is in possession of the complete and correct physical description and explanation of color vision, from the physics of light to the neurophysiology of perception. She knows all there is to know, and she’s got it all right.

Mary is color-blind. She has never seen a blue or red surface, only blacks, grays and whites. That is, she doesn’t know what colors look like. Sadly, she does not have the capacity for the relevant qualitative experience (I’ve always suspected that Mary has over-compensated for her disability in the pursuit of her chosen career). If this is right, then a complete and correct physical description and explanation of experience is lacking some information: what it is like to see colors (to use a phrase made famous by yet another exponent of the problem, Thomas Nagel). Now we have another putative mental “property,” and like the semantic property it appears to be unanalyzable into physical properties. There is even a noun, quale (singular of qualia), that denotes these qualitative feelings: the quale of this bite of chocolate I’m taking is this particular taste-sensation that constitutes my being conscious of the chocolate in my mouth. Conscious experience consists of qualia and qualia are not analyzable into, identifiable as, or reducible to physical properties.

Thus psychology cannot be naturalized. There is something called phenomenal description (the description of the quality of experience) that necessarily is always distinct from physical description. The study of experience qua experience is called phenomenology, but I will call the metaphysical problem, following the usage in contemporary philosophy of mind, “the problem of consciousness.” This is the subject of Chapter Three. There is a close connection between this problem as it is framed by contemporary philosophy of mind and the much older philosophical problem of the possibility of a radical difference between our experience of the world and the world as it actually is. In modern philosophy it is more common to put this as an epistemological problem (for example in the literature of skepticism). Both the English-language phenomenalists and the Continental phenomenologists of the early 20th century wanted to put metaphysics behind them, but I will maintain that progress here can only be made in the context of an explicitly metaphysical discussion. Nor would my conclusions be congenial to philosophers of that era: I will argue that the phenomenalists were in the grip of a disastrous misinterpretation of Hume and that phenomenology is impossible.

Like most people I tend to be drawn towards symmetry. Alas, Chapters Two and Three do not have symmetrical arguments. Whereas I break the problem of intentionality down into two constituent problems, the problem of representation and the problem of rationality, and offer positive theories to handle both, I will argue that the problem of consciousness is in fact a pseudoproblem and thus not amenable to (or in need of) any “theory” at all. Nonetheless even if one is persuaded, as I am, by the argument that the problem of consciousness is a pseudoproblem it turns out that there still remains something to say about metaphysics and consciousness and that discussion forms the second part of Chapter Three.

Philosophy of mind finds itself, at the beginning of the 21st century, to be at something of an impasse. For much of the 20th century operationalists had an agenda stable enough and productive enough that they were able to basically ignore the challenge of the phenomenologists, although the rejection of behaviorism as a popular psychology, after a long battle from Aldous Huxley’s iconic Brave New World through B. F. Skinner’s incendiary Beyond Freedom and Dignity, made the problem clear enough. (A crucial exception was Wittgenstein, but I will save that discussion for Chapter Three.) Gradually the dam broke and by the end of the 1980s thanks to Searle, Jackson, Nagel and others the post-“Analytic,” English-language philosophy of mind community acknowledged the problem of qualia as a central problem, and today one of the most thriving branches of the field, quite at home with the scientific neighbors in the area of “cognitive studies,” is “consciousness studies.” I will call those who take the problem seriously the “phenomenologists” although no doubt some will think that term comes with too much baggage; I ask the reader’s indulgence for the sake of exposition.

These new phenomenologists quickly set about demonstrating the inadequacy of functionalism and operationalist approaches in general as comprehensive theories of mind. For any qualitative experience (any quale) that appears to have a causal role in the production of behavior, the argument goes, one can conceive of a being with the functionally equivalent behavior but not the quale (a number of these “absent qualia” arguments, while mostly to the same point, are important enough to get their own discussion in Chapter Three). This might seem to be more of a problem for the advocates of phenomenology than it is for the advocates of operationalism but the opposite is true: if a functionally complete description and explanation of a person lacks any description or explanation of consciousness then functionalism is in the same position as Jackson’s Mary gedanken appears to put physicalism in general: it is not a complete theory of mind. In the literature this is often tagged as the “zombie” problem: the zombie is the allegedly conceivable functionally-complete but consciousness-lacking person.

The phenomenologists, for their part, have often accepted that the problem of consciousness does indeed thwart the naturalization of psychology, just as their older Continental namesakes did (although with considerably less enthusiasm). For example there is a well-developed line that a “property” dualism is inevitable, a kind of epistemological dualism that does not commit one to actual metaphysical dualism. I don’t think so: I think that metaphysical physicalism entails epistemological physicalism, on the grounds that that is the only possible significance of such a metaphysical assertion. There is a group that calls itself the “mysterians,” who argue that we just have to concede that there is no accounting for the relationship between the physical and the phenomenal. And one of the most noted writers on the topic in recent years, David Chalmers, had considerable success with his suggestion that metaphysical dualism is the right theory after all (admittedly the suggestion is made in a Berkelean spirit: we should just concede metaphysical dualism and move on). An exception to these various consuls of despair is Searle, and that is another discussion elaborated in Chapter Three. But with exceptions the phenomenologists find themselves with an apparent refutation of operationalist theories but without a coherent theory of their own.

The book you are reading is titled The Mind/Body Problems; the aim of the title is to draw your attention to the plural. The next section is, I think, straightforward, but it is one of the most important sections of the book.

The first horn of the dilemma in contemporary philosophy of mind

2010-10-10T13:49:00.001-04:00

We are put onto the horns of our current dilemma by good arguments, not bad ones. The first line of argument at the heart of contemporary philosophy of mind is exemplified by Alan Turing’s work and his “Turing test,” although perhaps the most important elaboration of the line is that found in the writings of Ludwig Wittgenstein, and the whole approach has its roots in the empiricism of David Hume. Hume argued that we were on firm ground when we could specify experiences that grounded our descriptions of and theories about the world. Hume identified “metaphysics” with the traditional, pre-empiricist philosophy of the “Schoolmen,” as he called them, and he is a typically modern philosopher in that he imagined that he had done away with a great deal of traditional philosophy altogether; at least, that was his aim. He understood that this radical empiricism had radical implications for psychology: he denied that there was anything that could be called the “mind” other than the bundle of perceptions and thoughts introspection revealed, and questioned whether anything that could be called the “self” (other than the perceiving and acting body) could be said to exist, for the same reasons. The “mind” and the “self” were for Hume too close in nature to the “soul,” a putative non-physical entity of the sort that the Enlightenment empiricist wanted to eliminate along with angels and ghosts.

The early 20th century heirs to Hume were the behaviorists. Too often today behaviorism is regarded solely as a failed movement in the history of 20th century psychology, but it is important to appreciate that behaviorism was an attempt, and a very powerful, respectable and still-interesting attempt, to naturalize psychology. It is also important to see that the motivation for developing behaviorism for the empiricist-minded philosophers and psychologists of the time was essentially metaphysical. The ghostly mental entities, figuratively located “in the head,” that were the nominal referents of psychological descriptions and explanations (“beliefs,” “desires,” “attitudes,” etc.) had to be washed out of the ultimate, natural semantics. Behaviorism proposed to naturalize psychology in a simple way: stick to a strict empiricist methodology. If the methodology of science was adhered to, ipso facto psychology would be a science. For present purposes “behaviorism” can be defined as the view that psychological predicates (“He believes that Boston is north of here,” “She is hungry”) refer in fact to observable dispositions to behave: behaviorism is a good example of “theory of mind” as semantics of psychological language.

Behaviorism is a full-blown theory of mind (a general semantics for the psychological vocabulary) that eliminates any reference to anything “in” the mind. On one interpretation this is simply a methodological prohibition on psychologists who aspire to being “scientific” from referring to these “inner” (that is, unobservable) mental states and processes. This version is variously called “soft,” “methodological,” “psychological” or (my coinage) “agnostic” behaviorism. A more radical interpretation is that the inner is an illusion, a historic misconception. This more radical version, the leading avatar of which is Wittgenstein, is variously called “hard,” “metaphysical,” “philosophical” or “atheistic” behaviorism. I don’t want to get sidetracked here by the complicated story about behaviorism’s varieties and the varieties of problems and objections behaviorism encountered. Just now what we need is to grasp and appreciate what was powerfully persuasive (and enduring) in the empiricist line of theory of which behaviorism is an example.

Alan Turing, thinking about computation and computing machines, took a behaviorist approach to the word “intelligence.” He famously proposed the “Turing test”: when an intelligent, sane and sober (that is, a somewhat idealized) person, interacting with a machine, can no longer see any difference between the outputs of said machine and the outputs of an intelligent (etc.) person, at that point we will have to concede that the machine is (actually, literally) intelligent as well. Machine intelligence will have been achieved. “Outputs”: the Turing test is usually conceived as a situation where there are a number of terminals, some connected to people, some to machines. Human interlocutors don’t know which are which. Questions are asked, comments are made, and the terminals respond; that is, there is linguistic communication (there is actually an annual event where this situation is set up and programmers enter their machines in competition). Turing himself never saw a personal computer, but he was conceiving of the test in roughly this way.

However, “outputs” could be linguistic, or behavioral (imagine a robot accomplishing physical tasks that were put to it), or perhaps something else (imagine an animated or robotic face that made appropriate expressions in response to peoples’ actions and statements). Nor does the candidate intelligent thing need to be an artifact, let alone a computer. I am following Turing in sticking to the deliberately vaguer word “machine” (although it’s true that Turing theorized that intelligence, wherever it was found, was some species of computation). Imagine extraterrestrials that have come out of their spaceship (maybe we don’t know if they’re organisms or artifacts), or some previously unknown primate encountered in the Himalayas, say. The point is that in the case of anything at all, the only possible criteria for predicating “intelligence” of the thing are necessarily observation-based. But after all, any kind of predication, psychological or otherwise, is going to depend for its validity on some kind of observation or another (“The aliens are blue,” “The yeti is tall”), and psychological predicates are no different.

Wittgenstein gives perhaps the most persuasive version of this argument in what is usually called his “Private Language Argument.” Wittgenstein holds that language is necessarily intersubjective. (In fact he thinks that it is not possible for a person to impose rules on their self, so ultimately he thinks that a private language is impossible, but we don’t need to excavate all of the subtleties of the Private Language Argument to see the present point about the criterion of meaningfulness, which is fairly standard empiricist stuff). If I say to you, “Go out to the car and get the blue bag,” this imperative works because you and I have a shared sense of the word “blue.” Without this shared, public sense communication is impossible, as when people are speaking a language that one can’t understand. Psychological words, just like any other kind of words, will have to function in this intersubjective way: there will have to be some sort of intersubjective standards or other for determining if the words are being used correctly (the two of us have to be following some shared set of rules of use). Wittgenstein emphasizes the point that, to the extent that psychological predicates are meaningful at all, they cannot be referring to anything “inner,” known only to the subject of predication. And for all of the problems and failures of the original behaviorist movement, it is hard to see anything wrong with this central point.

The term of art for any theory of mind that says that psychological words necessarily have to conform to publically, intersubjectively established standards and procedures of use in order to make sense is operationalist. Behaviorism is a kind of operationalist theory, and so is functionalism, to which I now turn, so I need the word “operationalist” to use when I want to refer to these kinds of theories of mind in general. Operationalist theories appear to handle some critical problems in the philosophy of mind, and constitute the first horn of our dilemma.

Functionalism can be defined as the view that psychological predicates refer to anything that plays the appropriate causal role. That’s a bit gnostic so I will unpack it with some history. Remember that according to Turing there is no difference between a human and a machine qua intelligent being once the machine’s intelligent performance is indistinguishable from the human’s. Acting intelligent, on an operationalist view, is just being intelligent, just as sounding like music is just being music. “Being intelligent” breaks down into many (perhaps indefinitely many) constituent abilities. For an easy example take learning and memory. Part of being intelligent is being able to learn that there are people in the house, say, and to remember that there are people in the house. Both an intelligent human and an intelligent machine will be able to do this. But the human will do it using human sensory organs and a human nervous system, while the machine will have physically different, but functionally equivalent, hardware.

This is the problem of the multiple realizability of the mental. It is one of the deepest metaphysical issues in the philosophy of mind. Around the middle of the 20th century philosophers of mind concluded that a literal reductive materialism, for example the identification of a specific memory with some specific physical state in a human brain, or of remembering itself with some specific physical process in human brains, committed a fallacy often referred to in the literature as “chauvinism.” These philosophers weren’t the first to see this: Plato and Aristotle, for example, not only saw this problem but developed some of the best philosophical analyses of the issue that we have to this day. I want to stress that once we accept any kind of operationalist theory, the problem of multiple realizability is undeniable. Humans, dolphins (among other animals), hypothetical intelligent artifacts and probably-existing intelligent extraterrestrials will all take common psychological predicates (“X believes that there are fish in the barrel,” say, or “X can add and subtract”). In fact the extension of the set of beings who will take psychological predicates is indefinitely large and does not appear to be fixed by any physical laws.

Functionalism, like behaviorism, is motivated by essentially metaphysical concerns, in the case of functionalism by the problem of the multiple realizability of intelligence. Functionalism abstracts away from hardware and develops a purer, more formal psychology: any intelligent being, whatever they may be made of, whatever makes them tick, will have (by definition) the ability to learn, remember, recognize patterns, deduce, induce, add, subtract and so forth. Although the more enthusiastic advertisements for functionalism like to point out (rightly enough, I suppose) that functionalism, in its crystalline abstraction, is even compatible with metaphysical dualism, functionalism is best understood as a kind of non-reductive materialism. That is, while the general type “intelligent beings” cannot be identified with any general type of physical things, each token intelligent being will be some physical thing or another.

This extends to specific mental states and processes as well, of course: the human, the dolphin, the Martian and the android all believe that the fish are in the barrel, they all desire to get to the fish, and they all understand that it follows that they need to get to the barrel. Each one accomplishes this cognition with its physical body somehow, but they all have different physical bodies. There is token-to-token identity (that’s the “materialist” part), but there is no type-to-type identity (that’s the “non-reductive” part). It is not coincidental that functionalism has been the most influential theory of mind in the late 20th century, the age of computer science. The designer (the psychologist) sends the specifications down to the engineers (the computer scientist and the roboticist): we need an artifact with the capacity for learning, memory, pattern recognition and so on. The engineers are free to use any materials, devices and technology at their disposal to devise such an artifact.

This realization that functional descriptions do not analyze down to physical descriptions (a realization at the center of Aristotle’s writings) is a great advance in philosophy of mind. It changes the whole discussion of the metaphysics of intelligence and rationality in a decisive way. In Chapter Two I will argue that operationalist theories in general can indeed provide an intuitively satisfying naturalistic semantics for predications of cognition, intelligence and thinking. To close this introductory discussion of the first horn of the dilemma I will quickly sketch the way operationalist theories also can be deployed to address another core metaphysical problem, the problem of mental representation and mental content. Then I will be able to define one of the most important terms in this book and one of the most difficult terms in philosophy of mind: “intentionality,” the subject of Chapter Two.

“Representational” theories of mind hold that it is literally true that cognitive states and processes include representations. To some this may seem self-evident: isn’t remembering one’s mother, for example, a matter of inspecting an image of her “in the mind’s eye”? Isn’t imagining a tiger similarly a matter of composing one’s own, private image of a tiger? There are reasons for thinking that mental representations must be formal, like linguistic representations, rather than isomorphic, like pictorial representations: How many stripes does your imaginary tiger have? Formal representations, like novels, have the flexibility to include only relevant information (“The Russian guerillas rode down on the French encampment at dawn”), while isomorphic representations, like movies, must include a great deal of information that is irrelevant (How many Russians, through what kind of trees, on horses of what color?). While there are those who argue for isomorphic representation, most representational theorists believe that mental representations must be formal rule-governed sets of symbols, like sentences of language. The appeal of such a model for those who want to approach cognition as a kind of computation is obvious.

Some of these issues between species of representational theory will be developed in Chapter Two, but for introductory purposes four more quick points will suffice: First, why mental representation/content poses a metaphysical problem; second, how we can define the often ill-defined word “intentionality”; third, which psychological words are taken by representational theorists to advert to mental content; and finally, how operationalist theories might be successful in addressing the metaphysical problem of representation.

The metaphysical problem is that symbols per se seem to have a “property,” the property of meaning, which does not appear to be analyzable as a physical property. This issue is addressed in philosophy of language, but language and other symbol-systems are conventional (albeit the products of long evolutionary processes); the location of the ur-problem is in philosophy of mind. Consider the chair in which you sit: it does not mean anything. Of course you can assign some arbitrary significance to it if you wish, or infer things from its nature, disposition and so forth (“All of the world is text”), but that doesn’t affect the point: physical objects in and of themselves don’t mean anything or refer to other things the way symbols do. Now consider your own, physical body: it doesn’t mean anything any more than any other physical object does. Nor do its parts: your hand or, more to the point, your brain, or any parts of or processes occurring in your brain. Your brain is just neural tissue humming and buzzing and doing its electrochemical thing, and the only properties included in our descriptions and explanations of its workings are physical properties. But when we predicate of a person mental states such as “He believes that Paris is the capital of France,” or “She hopes that Margaret is at the party tonight,” these mental states appear to have the property of referring to, of being about, something else: France, or Margaret or what have you. It looks, that is, like the mental state has a property that the physical state utterly lacks.

I can now offer a definition of “intentionality.” In this book, intentionality refers to two deeply intertwined but, I will argue, separable metaphysical problems: 1) the problem of the non-physical property of meaning that is implicit in any representational theory of mind (I will call this “the intentional property” or sometimes “the semantic property”), and 2) the problem of rationality, that is, the apparent lack of any physical parameters that could fix the extension of the set of beings that take predicates of rationality (or intelligence). The intentional vocabulary consists of words like “belief,” “desire,” “hope,” “fear,” “expectation,” “suspicion,” the word “intention” in its ordinary use etc. Psychological predication using these words is often called “intentional psychology” or “belief/desire psychology” or sometimes (usually pejoratively) “folk psychology.” The intentional vocabulary consists of all and only those words that appear to entail mental representation, often referred to in the literature as “that-clauses,” as in {A belief that “Paris is the capital of France”}, or {A hope that “Margaret will be at the party tonight”}.

On a widespread representationalist view these are propositional attitudes, in the respective examples the belief that the proposition “Paris is the capital of France” is true and the hope that the proposition “Margaret will be at the party tonight” is true. It is commonly suggested that, since these intentional states are individuated by the content of the propositions towards which they are attitudes, propositions must be represented somehow in the mind. Such a view commits one to the existence of the non-physical “property” of meaning. This is not (or at least not entirely!) an abstruse argument amongst philosophers: any model of the nervous system as an information-processing device makes this commitment, and the most cursory perusal of standard neuroanatomy textbooks is enough to see that they are saturated with this kind of language.

On my view naturalizing psychology requires that putatively non-physical “properties” be washed out of the final analysis in favor of solely physical properties (the only kind there are). That is, I think that representational theories of mind are false. To use the term of art in theory of mind, I am an eliminativist about mental representation and content. Mental representation will be the main topic of the first part of Chapter Two, which in many ways is the heart of the book. To conclude this introductory section I will briefly sketch how operationalist theories of mind might open the way toward an acceptably naturalistic semantics of the intentional vocabulary.

Behaviorism is also a kind of eliminativist theory: behaviorism eliminates (from the semantic analysis of the psychological vocabulary) anything unobservable at all, including private “inner” mental states and processes. Functionalism, behaviorism’s more sophisticated progeny, acknowledges that states and processes “in the head” (that phrase may be taken either literally or figuratively here) play causal roles in the production of behavior (“The thought of X reminded him of Y and he started to worry that Z…”), but still manages to rid the analysis of psychological predication of reference to mental states (to intentional states, in the present case). It does so by describing cognition functionally rather that physically. Take any sentence that includes an intentional phrase, say: “At the sight of his mother’s photo he remembered the crullers she used to bake, and this memory motivated him to go to the grocery and buy sugar, butter and unbleached flour.” The representationalist is, it would seem, committed to the view that a representation of the crullers is playing a causal role here. But a functional description of the cognitive process can substitute a generic functional-role marker thus: “At the sight of his mother’s photo he X’d, and this X motivated him…etc.” Now “X” can stand for anything that plays the appropriate functional role, and obviously this no longer commits us to the existence of representations or of anything else with non-physical properties.

As I said, the two problems of intentionality (the problem of rationality and the problem of mental content) are further separable. In Chapter Two I will first develop a naturalistic semantics for intentional predication, one that is eliminativist about mental content. Then I will offer a second argument about the problem of rationality that relocates the metaphysical problem outside of philosophy of mind. Both of these arguments acknowledge the validity of the operationalist maxim exemplified by the Turing Test: outside of some formal, intersubjective standards for identifying intelligence through public observation there can be no justifiable reasons for predicating intelligence of a being or for refusing to do so.

Metaphysics and method

2010-10-02T17:11:00.001-04:00

Metaphysics (or “ontology”) is the study of what exists (Aristotle called it the study of “being”). To many people today metaphysics seems anachronistic. Haven’t we settled the issue of what exists, they might ask, in favor of the physical universe? And isn’t natural science the way we produce knowledge about this universe? How could more work in metaphysics possibly generate any persuasive arguments, if “metaphysics” is not simply “physics”? Arguments about the relationship between the mind and the body that aren’t grounded in empirical research of some sort can’t hope to be legitimate in a world awash in data from experimental psychology, neuroscience, computer science, evolutionary biology, linguistics and the myriad of interdisciplinary areas of research that today we call “cognitive studies.” Isn’t a metaphysician a mere poet of speculation? Diverting at best, but such a person has no hope of producing useful knowledge. That, anyway, is the drift of the reaction one frequently gets when proposing to discuss the metaphysics of the mind/body problem. I will respond to this initial “meta”-challenge in two ways.

First, I completely embrace the spirit, and much of the letter, of this initial objection. I too take it as axiomatic that what exists is the physical universe (by “physical” I mean the universe of matter and energy, or maybe matter/energy; I don’t pretend to be sophisticated about theoretical physics). I don’t think that humans are composed of physical bodies and non-physical souls, like a traditional mind/body dualist. I think that humans are physical through and through, animals that evolved here on earth through a long process of evolution the contingencies of which were, and continue to be, bounded by the constants of biology, chemistry, and physics. I don’t expect to discover that humans are angels, or that the physical universe is an illusion and humans are non-physical spirits, or anything like that.

To be more specific, I have a view about the metaphysics of humans that I call anti-humanism, a loaded phrase taken as rhetoric but used here only to mean this: the universe may be as magical, mysterious and mystical as it may be; I don’t know anything about the ultimate composition or nature of the universe. I have no interest in making a brief for reduction, as if natural science has already revealed the nature of being, or even potentially could. I don’t even know what we’re talking about when we use that kind of language. My claim is much humbler: whatever nature in general is like, humans are like that. Humans are not miracles, if a “miracle” is defined as an exception to the laws of nature. I hold the anti-humanist view simply because I know of no reason to think that humans are miracles; I stress it because a deeply internalized assumption of human exceptionalism continues to be a barrier to progress across the whole area of cognitive science.

Which brings me to the second response to the objection that metaphysics is anachronistic: it is certainly not true that the contemporary community of educated people embrace anti-humanism as I just defined it. For one thing, a great many college students, most people walking down the street and the overwhelming majority of the world’s population today continue to think that the mind (taken, that is, in the metaphysical sense of some thing that exists) is something distinct from the body or, at least, that mental phenomena cannot be adequately described and explained in wholly physical terms. This conviction has many variants that range from traditional, usually religion-based beliefs about souls, afterlives and so forth to more modern notions, such as the view that a naturalistic view of human nature is perniciously reductive and to be resisted by the liberal-minded, or perhaps that science itself is nothing but a socially-constructed “conceptual scheme” with no particular claim to legitimacy, and so on. For another thing, very sophisticated versions of human exceptionalism exist in the academy (for example among some linguists), such that it is by no means established conventional wisdom that physical science subsumes psychology by metaphysical axiom.

That’s why the topic continues to be exciting. We live in a world where most natural phenomena, from the micro level of atoms, cells and molecules up to the macro level of galaxies and the universe itself, seem to be describable and explicable in physical terms. Physicalism (I mean by this term the metaphysical position that only the physical universe exists) is not totally triumphant (and it is a reasonable point that contemporary physics itself presents us with a still-mysterious and newly-strange picture of the universe). There are ongoing popular metaphysical arguments about evolutionary biology and about cosmology, for example. But it is a striking fact about contemporary culture that psychology (and by extension the behavioral and social disciplines) are still not considered to be integrated into our otherwise generally physicalist metaphysics. Put another way, while many people today have firmly internalized physicalist intuitions about organic life, say, or about distant celestial objects, physicalist theories of mind still meet with resistance even among secular, science-educated people.

A note on terminology: Consider three words, “materialism,” “physicalism,” and “naturalism.” There is a worthwhile philosophical discussion to be had about the relationships and differences between these three concepts. “Materialism” might be the view that matter (matter/energy) is the only thing that exists, “physicalism” the view that the physical universe is the only thing that exists, and “naturalism” the view that only nature exists. Obviously there is a lot of fleshing out to do to make those terms very coherent. I’m not going to work on that here. Connotatively “materialism” sounds the most reductive, “naturalism” the most open-minded, so people inclined to inject ideological considerations will linger on these distinctions, no doubt a potentially useful thing to do but not something that particularly interests me in the present context. I am going to paint with a broader brush and assume that my charitable readers will get the larger drift: these words all point towards a broadly naturalistic monism, versus metaphysical heterogeneity or dualism. I will mostly, but not exclusively, use the term “physicalism” and stick with my definition that this is the view that only the physical universe exists.

Metaphysics is not something that is replaced by physics. Physicalism is a particular metaphysical position. Everyone has metaphysical assumptions, articulated or not, whether they want to or not, and they always will. The person who chafes at the idea that there is still a need for explicitly metaphysical discussion is claiming that our shared metaphysical assumptions are currently stable, not that “there is no such thing as metaphysics,” although they may unreflectively put it that way. I agree that physicalism is currently the ruling metaphysical paradigm, at least among cognitive scientists, psychologists, philosophers and so on, and I too labor within this paradigm, albeit with some important qualifications that are discussed in the second part of Chapter Two.

It’s not enough, however, to just assert one’s acceptance of a broadly physicalist, or naturalist, metaphysical attitude. Our work here is not done. For dualists, including many philosophers working in the classical, medieval and early modern periods of European philosophy through to 19th century transcendental idealism, the “mind/body problem” was the problem of explaining the interaction of the physical with something non-physical. Plato and Descartes are examples of excellent philosophers who saw the problem this way. For the physicalist the problem is different (and, yes, there are third ways, such as Spinoza’s “double aspect” approach, that are important and useful and that will be discussed where appropriate). The physicalist wants to naturalize psychology: to integrate psychology into the broader naturalistic worldview. And that we have yet to do. To see this, I’ll conclude this preliminary discussion of metaphysics in general and get to the specific problems of philosophy of mind.

If “metaphysics” still sounds too far out, consider the relationship between metaphysics and semantics. Say someone is talking about angels. The word “angel” is the subject-noun in their sentences. In good faith (pardon the pun), we would like to understand what they are saying to us. “What are you referring to,” we might ask, “by this word ‘angel’?” If, as one might suspect, it turns out that our friend means to be referring to non-physical entities, some people will demure because they doubt the existence of non-physical entities per se. This is the source of the old cliché of the philosopher as someone who insists that we “define our terms”: philosophers are sensitive to the metaphysical assumptions revealed by language (and of course we’re all philosophers, just as we’re all musicians; these are basic questions that everyone asks, just as everyone enjoys a good tune). In that sense, metaphysics and semantics come to the same thing.

It’s not just entities but also properties that are part of existence, or of what we refer to as existing. In philosophy of religion (a useful example just because most people have thought about it) we find references to metaphysically interesting entities: God, angels, heaven and so on. In other areas, such as aesthetics and ethics, we find references to all sorts of metaphysically interesting properties: beauty, goodness, justice etc. Just as we might be skeptical of the existence of non-physical entities, so we might be skeptical of the existence of non-physical properties. That is, a physicalist might hold that all properties are physical properties (that is, that only physical properties exist) just as they hold that only physical entities exist. In fact we can just define “philosophy” as metaphysics and epistemology. Any discourse that makes metaphysically and epistemologically unusual references comes under the purview of the philosopher. These topics include (but are not limited to) aesthetics, ethics, logic, mathematics, politics and society, religion, the nature of science itself…and psychology.

Another introductory note on terminology: By “psychology” I don’t mean the academic discipline that goes by that name and in which specialists receive formal degrees. I mean the ordinary, everyday discourse, practiced by everyone, that we traditionally use to explain behavior. “Why did he leave the room?” “He wanted a drink of water.” “Does she like chocolate?” “Yes she does.” “Are you in pain?” “I’m OK.” I mean nothing more nor less by “psychology” than that kind of talk, and the assumptions and conceptualizations that underlie it. That is where we find the metaphysically interesting language.

Psychological language makes frequent reference to all sorts of mental entities and properties. In religious talk (to stick with the most obvious analogy) we find words like “God,” “angels,” “faith,” “prayer” and so on. When I say these are metaphysically interesting words I mean that they don’t seem to function in the way that grammatically similar words from more quotidian discourse do. I can understand “The table is in the room” without any metaphysical trouble. I cannot do the same with “God is everywhere.” English speakers typically have no trouble understanding the use of the existential verb “to be” in sentences about tables, but they do in sentences about angels. For an epistemological example, one does not have faith in one’s religion in the same way that one has faith in politicians (or vice versa!). The verb “to know” is being used in an unusual way. Philosophical enquiry is needed.

Similarly in psychology we refer to, among other things, “beliefs,” “desires,” “hopes” and “fears,” also to “pains,” “sensations,” “textures” and “tastes.” (In what follows I will identify and distinguish two fundamental kinds of psychological words. That will be some of the major business of the book, so for now I will just stick to this preliminary discussion of metaphysics and method.) It’s clear enough that these are metaphysically interesting words. I don’t “have” beliefs and desires the same way that I have nickels and dimes. I don’t even have any fixable number of beliefs and desires, whereas the current number of nickels and dimes in my possession is all too definite. Sometimes I can see that my friend has a bag in his hand and sometimes I can see that my friend has a pain in his hand, and seeing it (with my own eyes) is (outside of a philosophy class!) all I normally need in order to know it, but so different is seeing his pain from seeing his bag that many people are willing to say (but usually only inside of a philosophy class) that I don’t actually know about his pain at all.

To naturalize psychology would be to give an account of the meaning of psychological words such that they were no longer metaphysically interesting. Another way to put this is that a physicalist theory of mind is identical to physicalist semantics of psychological words. The whole enterprise is revealed to be much less outlandish than it initially appears once one sees that we are talking as much about the word “mind” as we are talking about minds, as much about the word “belief” as we are talking about beliefs, as much about the word “sensation” as we are talking about sensations, and so on. Nor do I have any aspiration, as some contemporary philosophers of mind do, to change the way we talk (in fact I will explain my reasons for some doubts that we could even in principle do this).

It’s not normative psychological language that has problems. Normative psychological language is chugging along out there in the real world just fine. It’s contemporary philosophy of mind that has problems. As a philosopher of mind myself I experience this personally: there are currently two types of theories of mind, in response to two problems, and I find the arguments that motivate the respective problems persuasive, and I find the respective theories that are offered in response to the two problems to be intuitively more or less satisfying. It’s just that they are apparently mutually contradictory. It is that experience of internal contradiction in my own thinking about the subject that has motivated the present book. Without it I wouldn’t, couldn’t have developed a contribution even possibly original enough to justify writing yet another book on the philosophy of mind after several decades when we have been awash in them, many of them written by some of our best living philosophers.

Follow-up on "Does the PI Literature Beg the Question?"

2010-05-26T08:55:00.003-04:00

I was pleased to get the large number of interesting comments to the last post. Here is the latest, from "Noldorin":

"You've raised some very interesting points here. Indeed, too many of the arguments relating to the relationship between the mind and body tend to take a circular form. Monism/physicalism is the easy resolution to this, which is the core of your stance (correct me if I'm wrong). To me however, this denies the emergent nature of the mind, and treats it as a mere automaton. Consciousness, almost be definition, is an emergent entity - it cannot be understood from anything but a holistic viewpoint, which is very much what modern neurology and psychology seem to suggest.

Of course, the dualistic view has own problems too, which you highlighted at the start of your article. I however prefer to resolve the issue in another way. To me, the mind is inextricably tied to the "hardware" of the brain, yet this does not mean the mind is nothing more than the brain. If we consider the simple thought-experiment of transposing the mind (or to be clear, the physical brain even) to another body, to me, the identity clearly follows the mind. More problems however arise when you consider the concept of a cloned body. (Ignoring the science, I think this is perfectly acceptable philosophically.) Hypothetically two identical bodies and brains may then exist at some point, from which they would consequently evolve and diverge. What then if the "original" mind has already ceased to exist by the time the cloned one comes into existence? Does that transfer the identity of the original person to the clone? While this can be resolve (superficially) by the physicalist's view, I am most inclined to accept that both identity and the mind cannot in general be distinctly labelled, but rather they exist in some level of hierarchy, which can branch and fork. In this sense, the mind is not independent from the body, yet nonetheless exists as some higher level."

Here is one of my basic schticks that I posted in the earlier comments but that Noldorin may have missed: Stomachs don't eat lunch. Persons eat lunch. This is not to deny that the stomach performs a necessary function (for a mammal at least, as it happens in the human case, although perhaps not necessarily for a person, which is a member of a much larger set than the set of all humans). The semantics of the phrase "eating lunch" is external, or wide: we understand "eating lunch" as something that a whole, embodied person is doing out in the world. Part of the sense of "eating lunch" is a denoting of a relation that the person has to his/her environment.

Of course where I'm going with this is to the "wide content" account of intentional predicates ("He believes that...", "She desires that...") developed notably by the Wittgenstein-influenced Hilary Putnam ("Brains in a vat," Twin Earth etc.) and recently elaborated with great lucidity by Tim Crane (Mechanical Mind, 2003)and by Andy Clark (Supersizing the Mind, 2008) among others (don't miss Bennett and Hacker, Philosophical Foundations of Neuroscience, 2003). This is a style of physicalism that accommodates the "emergent" intuition of Noldorin. In fact my view is that it is a mistake to identify mental processes with brain processes, or indeed with any processes located entirely inside one's skin (that would be internalism, or narrow content, tightly related to representational theories of mind, viz Jerry Fodor).

Brains don't think. They don't imagine, they don't solve problems, they don't remember, believe, desire, hope, fear, "picture," "hear," they don't dream or hallucinate or perceive. They do not "construct worlds." There are no images, words, or symbolic content of any kind "in" brains (there is no "inside" to a brain, except as there is an inside to a bone, or a stomach). Like eating lunch, thinking is something that a person does (I think that there cannot be disembodied persons, of course that follows from holding a physical-continuity theory of personal identity as I do).

I'm not someone to write over-long blog posts, let me end this one with the following consideration that I think is under-appreciated and illustrates the practical importance of this seemingly abstruse discussion (and this is the bottom line, I think, of Bennett and Hacker's excellent book): if it is a mistake, as I think it is, to hold to a representational theory of mind, or even an information-processing model of nervous system function, then so long as we do we will be sabotaging ourselves from understanding what the brain really does. We understand (I take it) what the stomach does, that is, the role that the stomach plays in the overall process of the human eating lunch. But so long as we commit the homuncular fallacy - the fallacy of thinking that the brain helps the human to think by thinking itself - we cannot come to understand the real role that the brain plays in the overall process of the human thinking. In fact it appears that under the current theoretical regime (representationalism) we have absolutely no idea.

Does the "Personal Identity" Literature Beg the Question?

2010-04-18T14:30:00.003-04:00

A standard line in "personal identity" goes like this: Suppose your mind were put into another person's body, and vice-versa? Which person would now be "you"? It's pretty reliable to assume that if one puts the issue that way to a philosophy class, most people will have the intuition that they follow their mind: that "they" will now be "in" the other person's body, and thus the person embodied by that body will now be "them." Thus theories of psychological continuity have been more popular than theories of physical continuity since the time of John Locke.

I suspect that this is all wrong or, like the man said, "not even wrong." That is, in order for supporters of a psychological continuity of personal identity to be wrong it would have to be possible (conceivable) for them to be right. But it's not. The whole discussion is question-begging. An argument is question-begging when there is a premise in the argument that could be questioned, but isn't. In this case, that premise is, "There is something that is 'mind' that can be distinguished from 'body.'"

If there was something that was "my mind" that could be distinguished from my body, then it would be possible to imagine my mind existing independently of my body. That is what I'm doing when I imagine my mind in another body (or in heaven, or just out of my body, or whatever). Now, it seems as if we can imagine such a circumstance: we have a rich tradition of fiction, for example, that imagines minds switched between bodies, or the souls of dead people haunting the present world, etc. So the tricky part of my claim is the argument that, while you may think that you can (obviously, unequivocally) imagine your mind existing without your body, that is an illusion: in fact you cannot do that. For that is my position.

Today I'm thinking that maybe some arguments about skepticism can be deployed here. Someone says that there is a real issue as to the existence of the external world, say. It might exist, or it might not. I don't think that this is a coherent question. My view is that I neither "know" nor do "not know" that the external world exists: it is a spurious application of the verb "to know" in either case. The "external world" is not something separable from my experience.

The argument that persuades me here is one common to Zen Buddhism and to Wittgenstein, although I think that it is also the view that emerges from a correct interpretation of David Hume. The key is to see that "the world" does not collapse into "the self" any more or less than the self collapses into the world (the common German, Kantian interpretation of this material - Buddhism, Wittgenstein - tends to miss this crucial point). My world is the world as it is constituted by my body. In the absence of my body, this world also is absent. To say that my mind might be in another body is equivalent to saying that my world might be experienced by another.

Well that's vaguer than I'd like, but on the right track. Notice that there's another route to go here: one might make arguments to the effect that there is no such thing as "mind" at all. I think that that is also a valid way to go, and brings the question-begging nature of the traditional personal identity literature into clear focus. If there is no such thing as mind then there is no question of an alternative between psychological and physical continuity. Physical continuity, in that case, is the only coherent option.

The Large Hadron Collider and the Problem of Fate

2009-12-16T13:53:00.005-04:00

A couple of nights ago I came across some New York Times reporting on the Large Hadron Collider that discussed some questions that were distinctly metaphysical ones. No, I don't mean the theories that the collider may create a black hole or some sort of "antipathet-o-matter" that could destroy the world. Who the hell cares about that? No, the question I have in mind is, could it be that the Higgs boson is so antithetical to the actual universe that the universe will sabotage the accelerator from the future?

To see the problem (in metaphysics it is commonly called "the problem of fate"), say we take a proposition about the future: "You will eat pizza next Thursday." Specify this proposition in all the appropriate ways to you and next Thursday etc. It looks like this proposition has a truth value. That is, it's true or false. It doesn't look like one has the option of saying "neither," because after all you will or you won't. So it seems that there exist today facts about the future: the truth values of the propositions. (Aristotle thinks about this in De Interpretatione.)

In classical times this problem of fate was motivated mostly with the concept of God (or the Gods): if God has foreknowledge of everything (she is omniscient), then she knows whether you're going to eat pizza next Thursday and if she does so know, necessarily you're going to eat it. That's what the Oracle at Delphi could see, which is why how one phrased the question was so important (mistake for Xerxes to ask, "Will a great kingdom fall?" for example). Or maybe they were just really, really stoned.

Notice that this is not the same metaphysical problem as the problem about free will vs. determinism. That is a problem motivated by the concept of God's omnipotence or, laterly, by Newtonian models of "mechanical" physics: your actions are the result of chains of necessary causation such that you cannot substantiate your claim to be freely choosing them.

The problem of fate, on the other hand, is motivated by pointing out present facts that seem to entail future facts: God knows you're eating the pizza, there's a proposition with a truth value etc. Just thinking in purely metaphysical language (for the simple reason that I'm incompetent to discuss the physics!), it's got to go something like this: The Hibbs boson is antipathetic (for here unspecified physical reasons) to "this" universe so fundamentally that one can predict that Hibbs boson-detection is impossible. It is perhaps not necessary to interpret this effect as literally a cause from the future. Perhaps aversion to Hibbs bosons is a permanent disposition.

Apropos of nothing at all it does seem useful to look at the modal language in terms of sets of possible worlds: "possible" means true in some PWs, "contingent" means false in some PWs etc. It's not clear to me (nor perhaps to them, who are taken with other directions of argument) whether the authors mean: is the Hibbs boson antithetical (I'm deliberately using a different adverb each time) to "the universe" contingently (because of some of this particular world's properties), or necessarily (in all possible worlds)? After all, we don't know any other way, in logic anyway, to model modal operators at all, other than to formalize computations over sets. Leibniz made Spinoza's God a moral agent by explaining how God had actually made a choice: He chose the best of all possible worlds.

Or if we are asking about time, similar intimations of fate emerge. If time is a dimension, then wouldn't I be distributed across the dimension of time the way I take up discrete parts of space (that filled by my left hand and that filled by my right)? On this view I become a "spacetime worm," elongated through time when looked at from a meta-temporal perspective. Such a model (assuming that time is a dimension) eliminates change and even becoming and passing away: we experience different "time-slices" of a thing, but they are all co-present looked at meta-temporally. In which case the future, once again, turns out to already be what it is: the word "present," like the word "actual," is a mere indexical, a word that takes its meaning in context ("now," "then," "you, "me"). One thing I like about this reasoning is that it is what one gets, so far as I can see, from taking seriously the suggestion that time is a dimension, which is an idea that a great many people would endorse. And yet the spacetime worms seem so bizarre.

Anyway, my conclusion here if I were lucky enough to have one would be that when the NYT article compares the Large Hadron Collider to "someone who goes back in time to murder his grandfather," it looks to me that the claim is basically that, granting you're certain that the Higgs boson, although somehow at least conceivable (sounds like maybe a use-mention equivocation there), is nonetheless an impossibility in this world then you can be equally certain that a device designed to bring them into this world will fail. But that's not really an example of future causation. That's just saying that it can't be done.

Fodor and Spinoza

2009-11-02T11:43:00.003-04:00

Spinoza has what is called a "double-aspect" theory of mind. Spinoza argues that the universe is both the mind and the body of God. Thus everything comes under both a physical and a psychological description. This is a promising line of argument for philosophy of mind: if Spinoza is right, our project is not to reduce or translate the psychological to the physical. (A puzzle is what is called Spinoza's "panpsychism": on his view everything comes under both descriptions. What seems promising in the case of humans is just mysterious when said about, say chairs.)

Last week during class it occured to me that Jerry Fodor elaborates a line of reasoning that has some striking similarities to Spinoza. (I'm writing this here in class with the students, by the way.) Fodor's idea is that the semantic properties of the intentional mental states/processes and the physical causal properties of the brain states/processes might come together at the level of syntax. In a way Fodor pushes the approach further than Spinoza: his appeal to the formal structure of the grammar of the proposition, on the one hand, and the formal structure of the physical causal mechanism, on the other, could serve as the bridge between the two "aspects" (descriptions), thus producing "psychophysical laws," lawful relations between the two kinds of formal organization.

Notice that it's going to turn out that the brain (or nervous system, or body, or what have you) is also formally organized. My view is that (so far at least) this is right, and important: traditionally (Plato, Descartes) the formal structure of the rational mind was a metaphysical bar to translation between the intentional and the physical. But for an approach like Fodor's to work, it must be that the physical system is also something that comes under a formal description. It is the two formal descriptions that might map onto each other. If this is true than we can draw two conclusions.

First, there is no metaphysical problem here that is unique to the philosophy of mind. The rational structure of thought is (just) another instance of the formal structure of physical objects in general. The question about why the physical universe is formally organized may be interesting and important, but once we see that it is a general metaphysical problem we have effectively overcome this particular problem qua a problem for philosophy of mind.

Secondly, another bit of mysterious 17th century philosophy is called to mind: the "synchronicity" of Leibniz and Malebranch. Here the idea was that some third causal power (they used "God" here in a technical sense) has caused the mind and the body to be coordinated. This is also not as strange an idea as it seems at first. The formal structure of the world informs both the form of the body and the form of the language/mind.

I continue to think that there are no "representations" in the brain, and that intentional predicates are made of whole persons, not brains. But my appreciation of Fodor has deepened. The main problem I have with Fodor is that his arguments have been so extensively elaborated (by him!) that they are a kind of rabbit whole; one either writes a book on Fodor, or leaves him alone.

Etiology and Meaning

2009-09-28T11:44:00.004-04:00

Two people have the same (true) belief. However, one person has the belief because of personal experience. The other person has the belief because a clever lawyer has talked him into it, using deceptive arguments. In what way are their respective beliefs different? The propositional content is the same, and the proposition is true. And yet one has the intuition that the two "beliefs" are not the same kind of mental state. As Plato sees it in the Theatetus (200e-201e), one of them has knowledge and the other does not. One can have a belief by accident, or for the wrong reasons. Thus there is a difference between an accidentally true belief and a belief that is true for the right kind of reasons. One might compare such a belief, as Hilary Putnam does in his article "Brain in a Vat," to an ant trail, say, that bore a resemblance to a face. That would not really be a representation of a face, and nor would one really know anything about the world when possessed of a representation of the world that was only accidentally true.

To see the metaphysical point, imagine that a skywriter perfected the art of cloud-portriature: for a price he can render a likeness of anyone you choose in the medium of clouds, let's say Elvis. Suppose another cloud, unmanipulated by any skywriter, happened to form next to the cloud-portrait. The two clouds might be molecule-for-molecule identical, and both might have the same uncanny similarity to Elvis, but the cloud-portrait seems to differ from the natural cloud in having the property of meaning, or representing, Elvis. Here's a final example that makes just the same point: one day you notice that you have two copies of the city phone book. Thinking nothing of it, you keep one upstairs and one downstairs. You've used them both any number of times, for example to call out for your favorite pizza. However, unbeknownst to you, one of these objects is not a phone book at all. Through a near-miraculous event of quantum randomness (just making that up!), a doppleganger "phone book"-object has appeared in your house. It is both physically and functionally identical to the actual city phone book. Except for one thing: it contains no names, addresses, or phone numbers. It contains accidental conglomerations of matter that resemble such symbols, but it does not contain any actual symbols.

There is a conclusion wrapped in a moral wrapped in this point. The moral is that the significance (the intentional/semantic content) of a symbol is not just a function of the physical properties of the concrete symbol (the physical token), nor is it (more surprisingly) picked out by the functional role that the symbol supposedly plays in some larger process. The significance of a symbol (a name, say) depends on the etiology of the symbol, the process through which that symbol came to function as it does. "Meaning" is a complex relational property, a description, really, of relations between some person or persons and the world. Putnam's slogan for this moral is "Meaning just ain't in the head."

Notice the close affinity between Putnam's externalism and Saul Kripke's account of proper names as "rigid designators." (The affinity is not coincidental, as both philosophers are inspired by Wittgenstein.) Kripke claims that a symbol is an actual name of a thing or a substance just in case that symbol was originally used to designate the thing or substance in question. The payoff of this simple account is that the "meaning" of the name turns out to be nothing more than the history of that symbol in human behavior. There is no mysterious property of meaning left over.

The conclusion from this moral is about intentional predicates (predicating "propositional attitudes" of persons). When we say that {Sam believes that "The fish are in the bucket"}, externalist approaches hold not only the relatively clear point that intentional states are not any sort of brain- or body-state "in the head" (they are predicates of whole embodied persons), but that they are not "mental" states at all, they are "states of affairs": historical and behavioral relations between the person and his/her environment. Seen this way they need not advert to any "mental content": externalism is eliminativist as to mental representation, at least insofar as intentional descriptions are read as adverting to mental representations. The semantics of words like "belief," "desire," "hope," "fear" and so forth are handled without reference to internal "states." There are all sorts of causes inside the body of the person, of course, but these can all be described functionally within the context of the overall intentional description (and only within that context). To say that my intentional state is about something outside of my body is to say that I am in a certain relation to something outside of my body. (Nor is there any reason to think that this account fails for imaginary things like Santa Claus: I am not imagining that Santa Claus is in my head, I'm imagining that he's in my chimney.)

Ten Basic Articles for The Philosophy of Mind

2009-07-30T09:52:00.008-04:00

A facebook friend tagged me on a note: he wanted everyone to list "Ten philosophy articles that blew your little fucking mind." The stipulations were a) to name the first ten that came to mind, articles of personal interest and b) to restrict oneself to journal articles. I'm not sure about his phraseology, but I did take a minute to think of the ten philosophy articles that first came to me.

Confession: I barely read articles any more. There comes a point where one must write things, not read them, and I’ve been there for a while. Nor am I endorsing anyone either in terms of quality or rightness. These are the ten that came to me. My list is tightly focused, and does not represent the breadth of my interests or reading by any means. As I said, I don't really read much of the gladiatorial nit-picking that goes on in the journals. But of course that is only a matter of taste. I paint with a relatively broad brush, I guess.

The exercise turns out to be useful for me as some workbench stuff for my project on the metaphysics of the philosophy of mind. It's very much "the basics" for me. It also will serve as the bibliography of my fall philosophy of mind class. So a nice little exercise found whiling away some minutes on facebook, thank you Devon B.

1) Daniel Dennett, “Why the law of effect will not go away,” Journal of Social Behavior, 1978. The theory of natural selection is not a biological theory, it’s a proof of mathematical logic: not the kind of thing that could be “false.” Classic Dennett: simple as pie, closes the discussion. People think Dennett must be an overrated philosopher because of his success as a popular writer, but this is definitely an underrated article. I also find Darwin's Dangerous Idea (1995) to be one of Dennett's best books. My two basic criticisms Dennett in general are 1) I think his conclusions about the minds of non-human animals are a failure, and 2) it may be that reductive materialism fails in a way that he does not acknowledge, given his apparent identification of Enlightenment ideology with reductive materialism (contra "sky hooks").

2) Jerry Fodor, “Fodor’s Guide to Mental Representation: The Intelligent Auntie’s Vade-Mecum,” Mind, 1985. I’m an eliminativist about mental representation. Fodor of course is an intentional realist all the way. He fascinates me. A brilliant, eccentric writer. I would also mention “Why paramecia don’t have mental representations,” Midwest Studies in Philosophy, 1986. My basic issue: I take Wittgenstein's point that any naturalized account of anything isn't going to refer to intentional or semantic "properties," or to any other kind of non-physical properties, so I'm not disposed to representational theories of mind. But it might be that I take all that back. That's one of the questions that continue to sustain my interest.

3) Donald Davidson, “Mental Events,” Experience and Theory, 1970. His exposition of “anomalous monism.” Another great philosopher who I think I don’t agree with. I tell students in my philosophy of mind course that if they can do exegesis of this one and get it all, and get it right, they get an “A.”

4) Hilary Putnam, “Brains in a vat,” Reason, Truth, and History, 1981. An actual phonebook denotes actual names and numbers, but an identical object without the right etiology would not. Now that’s philosophy! For a long time I just waved my hands at the “Twin Earth” stuff, or I should say waved the white flag. Nowadays externalism/wide content is a crucial part of my overall position: I think intentional predicates are predicates of whole persons, and that gets the "meaning" out of the head. Certainly one of my all-time favorites.

5) David Lewis, “Mad Pain and Martian Pain,” Readings in the Philosophy of Psychology, 1980. A really hard article. I continue to feel resistance to it although at this point I agree with Lewis that the problem of qualia is a pseudoproblem. I tell students that a good philosopher is “sporting.” Lewis is very sporting. Don’t ask me to explain that any further.

6) Jaegwon Kim, any of the articles collected in Supervenience and Mind: Selected Philosophical Essays, 1993. The supervenience (multiple realizability) of intentional states is a metaphysical problem right at the heart of the mind/body problem. It is the essence of functionalism (the thing one has to understand to motivate functionalism). It is the link to Plato. Kim is one of my most important teachers.

7) Paul Churchland, “Eliminative materialism and the propositional attitudes,” Journal of Philosophy, 1981. I can’t say I care for the Churchlands much; she disses Wittgenstein in a way that alienates me, and their view is the opposite of mine: they hold that intentional psychological explanation may be eliminated, but mental representation cannot be, I hold the reverse. But I had to admit that this one had to be on the list. Basics. (I think Paul Churchland's The Engine of Reason, the Seat of the Soul, 1996, is the best basic statement of their view.)

8) Saul Kripke, “Identity and Necessity,” Naming, Necessity and Natural Kinds, 1977. Famously elaborated in Naming and Necessity, 1980. The argument is that “pain” necessarily refers to the feeling of pain, and necessarily cannot be identified with some physical state (“C-fibers firing”). Notice how this engages with his subsequent interpretations of Wittgenstein (Wittgenstein on Rules and Private Language, 1982): W. holds that no words can refer to “inner experience.” Which brings me to the last two articles.

9) John Searle, “Minds, Brains and Programs,” Journal of Behavioral and Brain Sciences, 1980. It was crucial for me to realize that a) I agree with the conclusions of both this article and the next, and b) these two conclusions appear to be mutually exclusive. That is, both the Chinese Room Argument and the Turing Test Argument persuade me, but it looks like one of them has to be wrong. Resolving this is a major part of my project The Mind/Body Problems. Point number one is that we have not one but two metaphysical issues here and we can make progress if we disentangle them.

10) Alan Turing, “Computing Machinery and Intelligence,” Mind 1950. Basically a classic statement of philosophical behaviorism. If you can see how Wittgenstein is more nuanced and deeper than this, you’re starting to appreciate Wittgenstein. What is the same is that Turing and Wittgenstein both take the semantics of psychological terms to be necessarily public.

Agnosticism and Philosophy

2009-07-13T07:42:00.007-04:00

This is a response to the really excellent round of comments published at the end of the last blog post. I think the substance of the respective comments is consistent enough not to do a "1),2)" kind of thing (that I often do, finding distinct arguments). But this topic is also fun, I notice, because everyone's got something to say.

Kevin Vond has in the past expressed to me that metaphysics, in any literal sense of that word, might be impossible if our conceptual structure was so 1) arbitrary: could have been radically otherwise within the same natural world, and 2) important in the role it played in our science, our general describing and explaining of the world, for us to ever be in a position to claim that we were actually doing "metaphysics." (And interesting that Kevin tends to be the critic of Wittgenstein vs. my attempts to apply what I take to be Wittgensteinian interpretations).

This is recognizably a descendant of German Idealism, and of course it is the whole drift of the Continental version of language philosophy (Habermas,Foucault, Derrida) of recent decades. It is also the popular view: the story one gets from an intelligent person with a passing interest in philosophy. I am part of a resurgence in metaphysics that has developed among English-speaking philosophers over the past thirty years or so, I think it is to some degree a consequence of the enormous attention that community has given to the philosophy of mind for many years.

I do think that what I like to call "metaphysics" may, for the existentially squeamish, be translated to "semantics." But I for one think that I can think about what sorts of things exist. Probably this all starts in thinking about materialism and the mind/body problem. I studied the metaphysics of universals, say, or propositions, possible worlds, essences and all sorts of things motivated by trying to get a handle on the metaphysics of reductive materialism vs. functionalism etc. N.N. mentions Alvin Plantinga, his debate with David Lewis about possible worlds as a battleground for nominalism vs. Platonism is out towards the deeper waters.

So first I want to talk about Kevin's experiments with concepts in his comment here. Let's think about "America," "justice," "God," and "the external world." If Kevin is right, all of these concepts ought to function in the same way. I like the anthropological behaviorist (a kind of reading of Wittgenstein) criterion that we can be said to be communicating when our communicative act makes a difference, when a person's choices are influenced. This is a definition of "meaning" intended to be eliminativist about Platonic entities, about some nonreducible semantic "property" and so forth.

I think that {"America" and "ethics"} are distinct from {"God" and "the external world"} as subjects of sentences thus: "I believe/don't believe that X exists." By the way I don't need to suggest that agnostics are disengenuous, only that they are confused. I take it that confusion on the present issues is the problem, not wanton disregard of these issues (fully understood!). We might say that "America does not exist" for any number of reasons. We might be talking to an American who was too nationalistic, or we might be talking to a foreigner who was too anti-American. Looks like the same case: we want them to see that they ought not be using the concept to do so much work, because it is leading them into reactionary territory. We want them to use their imaginations a little more and appreciate that the concept "America" is highly complex and has its explanatory and justificatory limits. That is, when we say that they go "too" far, we mean that we no longer accept that their account of things is reasonable. Fair enough. But notice that we cannot possibly mean to make a blanket metaphysical claim such that we claim that every time you mention "America," you are talking about a non-existent entity that in fact has no explanatory or causal role to play in our talk about the world. People just don't talk that much about unreal things. I know that sounds fast, but let me elaborate using the concept "ethics."

What happens in the undergraduate ethics class is, there's always someone who argues that "ethics does not exist." This has to be a metaphysical claim, and it has to be wrong. It has to be a metaphysical claim because it can't be any kind of pragmatic claim: it's a strange description of reality to say that "ethics doesn't exist" if your own metaphysical attitude tends to hold that the only thing there is to "existing" is what people think about and talk about all day. Whatever that is, the epistemological idealist is also, by definition, committed to saying it's real, if "knowing" is only a matter of having a concept that is functioning to influence behavior. Thus, as with "America," I sometimes say "There is no justice" (I admit that I might never say, "There is no ethics," but I could to the same end). For example when I am talking to my students about the importance of education and having a good future. I want them to see that an education is a precious thing that few people receive. I'm giving them some tough talk. But that we live in a world where we are confronted with ethical problems is as nonnegotiable as that we live in one where we are confronted with America.

"God" and "the external world" are not like that. Let's think about "the external world." One can't say, "Well look, we talk about the external world all the time. Not a minute goes by that we don't think and talk about the external world: same as ethics." But this is wrong. We never talk about the external world, if we mean by that something that might not exist given the experiences that we are having right now. Wittgenstein thought that there could be no propositions about ethics (or aesthetics: values in general), if by that a philosopher meant that he was explaining why some things are good and some things are bad. They just are, W. insisted, detecting a limit to language (this is what he and Popper got into a fight about that is described in the book Wittgenstein's Poker, that I haven't read). Note that here we can clearly see the empiricist Wittgenstein: Hume, Mill, the Modernists all share in this non-cognitivist tradition, vs. Continental rationalism.

But he thought it was nonsense to talk about either "the external world" or "phenomenal experience" if one claimed to be talking about anything over and above description of plain experience. (That is a basic reason why I am interested in Wittgenstein: I think he has a good argument for the elimination of phenomenal properties.) If God is (according to you) something in the world, then maybe it is something that exists or does not exist, and that you cannot now know about for one reason or the other. But if God is global the way the external world is global then the concept plays no real role and thus refers to nothing. If we are talking about the kind of thing about which one can neither "know" nor "not know," then agnosticism is impossible to the extent that agnosticism is the claim that "I do not know whether God exists."

However, Wittgenstein also appears to hold that there was "spiritual" reality that was as much a part of the (inexpressible) world as values. He himself took these things to be among the most important in life. That is what gets us finally to the concept "God." It looks like I can use the concept of God to the same rhetorical effect as in the first two examples. I can influence others by saying "There is no God!" I'm trying to shake up a hidebound thinker of one sort or another: a narrow dogmatist, or a paralyzed fatalist, or a self-pitier, or any number of other cases. Of course we also very frequently do this by saying "There is a God!" I'm pretty sure most people (both of us) who have read this far would interpret people, who mentioned God a lot while discussing what to do in daily life, as talking about some ethical character of the world: aiming for good outcomes and to avoid bad ones. But there is another thing, and maybe Plato gets it right.

There is the organized nature of the world. Now let me state out front that I take that in no way to demonstrate the existence of some "designer." In fact to claim to explain design by appeal to a designer just pushes the problem back a step: from whence the designer? It is a perfectly vacuous argument, taken that way. But I see the formal organization of the world as a plain fact like the existence of ethics: the world is like that. This may commit me to some kind of dualism after call: if "The world exists" is not the only existential truth, if "the world that exists is formally organized" is also true and ineffable, then Plato is right: there are two distinct ontological facts: 1)the bare existence of matter/energy, and 2) its formal organization. If that is what is taken as "God" (Plato thought it was "the Good," the source of intelligibility and value in the world), then that is something real that might not have existed, but does.

But that's perfectly acceptable as a pagan fact. I don't need to add God to that. Formal organization is already doing the work. Why is the universe formally organized? Why does it exist? There is no sense of "might/might not be" in either case. Not a subject of "belief" at all. If God is like that, agnosticism is impossible.

"Agnosticism" is Not a Theological Position

2009-07-08T14:15:00.000-04:00

A "theological position" would be an opinion of some sort (that's the "position" part) about something (say, existence or lack thereof) specifically about God (that's the "theological" part). "Either God exists, or God does not exist" is a theological position, because it contains the premise that both sides of the disjunction make sense. Put in metaphysical terms: that it's possible that God exists, and possible that God does not. But I'm not sure the agnostic is entitled to that much.

This is because the agnostic looks to me to be committed to the view that "Knowledge about God's existence is impossible." I think this is necessarily true about the agnostic because it makes no sense to say, "I choose not to have a belief one way or the other about X." As Socrates insists, one believes what one believes, whether one wants to or not. The attempt to reflect on our own beliefs, to honestly and courageously evaluate our reasons for holding them, is the beginning of philosophy. That is why "Because my family raised me to believe in God" is not an adequate answer to the question "Do you believe in God?" The question is about one's beliefs themselves, not the etiology of those beliefs, although that may be revealing (as it is, embarrassingly, in the example).

If this is so then another problem for agnosticism is that it is a consequence of a general epistemological attitude, that is, an attitude towards knowledge in general, and nothing particular to do with God. Aristotle's objections to Plato's metaphysics, Hume's objections to 17th century rationalism's metaphysics, are epistemological arguments with general application. Aristotle and Hume, hearty philosophers both, breathed deep and followed Socrates' dictum: they concluded (for closely related but interestingly different reasons) that they believed that various putative entities did not exist. They were willing to accept the consequences of the epistemological standards that they had set for themselves.

The agnostic wants to be a kind of sceptic: not sceptical of God's existence, but sceptical about the possibility of knowledge of God's existence. The move is to avoid the unpleasantness of denying God's existence by denying the possibility of knowledge of God's existence. Wittgenstein would say, "When you say that asserting God's existence or denying God's existence is impossible, because there is no way of knowing which possibility is fact, you are (merely) stating that it makes no difference, that neither proposition carries any meaning because there are no pragmatic consequences either way." That is he would apply his general criticism of sceptical arguments. In fact Wittgenstein holds that propositions about spirituality are impossible for the same reasons that he holds that propositions about aesthetics, ethics and phenomenal experience, for examples, are impossible. But a crucial point here is that he denies that this makes them insignificant (as Hume or A. J. Ayer, say, might do): he affirms the great significance of many aspects of experience that lie beyond the bounds of language.

Where does this leave the agnostic? (I am fighting off the urge to go on to Kierkegaard.) The agnostic cannot say, "I believe that God might exist or God might not, but I believe that knowledge of which is true is impossible." This is self-contradictory. In order to (really) believe that God might or might not exist, one must believe that there are (somewhere, somehow) reasons for believing one or the other. But the agnostic must claim that there are no such reasons, else why not examine them with Socrates and the gang? (Just as an aside, I think that there are reasons for and against believing in God: thus I am not agnostic, even if I have not reached a conclusion.) No, the agnostic is simply refusing to examine his or her own beliefs. Pascal was right: just doesn't want to get into trouble. Agnosticism is a refusal to do theology, not a theological position.

Buddhism and Guilt

2009-06-29T14:02:00.003-04:00

There are two issues to think about when we consider the relationship between Buddhist teachings and guilt:

1) Buddhism is primarily a preventive approach to wrongdoing, rather than a curative one. This is wise: much better to prevent bad things from happening than to have to deal with them once they have happened (a failure to recognize this is, maybe, the main problem with modern medicine, for example). Someone who cultivates the discipline to follow the Eight-Fold Path will, to the extent that they succeed, succeed also in doing no wrong. Basic Buddhist teachings are primarily aimed at cultivation of right being. They do not tend to dwell on atonement and expiation.

2) The First Noble Truth of the Dharma, that all life is suffering, refers of course to all forms of suffering. But as a human cultural artifact, Buddhist teachings over the centuries pay particular attention to mental suffering: negative thoughts and feelings. I do not wish to digress into a discussion of variants on Buddhist teachings here (trying to be brief), but it is worthwhile to point out that Tibetan (Tantric, Mahayana) Buddhism stresses the essential goodness of human nature and aims at liberation through positive self-realization, while Zen (Chinese, Taoist) Buddhism stresses the non-existence of the self and aims at liberation through selfless mindfulness (I have no intention here of judging between the two or even claiming that they are fundamentally different: I neither favor any school nor claim that there are ultimately fundamental differences). All Buddhist teaching aims at the end of ego-suffering through identification with the whole world (nirvana).

What I want to think about is the problem of real guilt. That is, for the sake of discussion, let's assume that one has in fact acted wrongly: willfully transgressed one's own moral principles. It is not a question of being "made to feel guilty" in some illegitimate way, and it is not an illusion of the ego, as when the ego leads us to think that negative outcomes are a result of our actions as a way of making us feel significant. (And perhaps there are other examples of false guilt.) No, let's assume that we are actually guilty. It's not impossible!

Buddhism teaches us that only ourselves suffer from the negative thoughts and feelings that we are experiencing. This is one of the most important insights of Buddhist psychology. Say someone negligently ran over my foot with their car and broke it. They may be rightly called upon to pay for the treatment or some civil responsibility like that. But they, the negligent driver, are hardly the right person to help to heal my injured foot. I will need a doctor for that, and above all I will need to follow the regimen, practice the physical therapy, and do everything necessary to cure my foot. That will be wholly my own responsibility.

Negative thoughts and feelings are like the injured foot. It is not a question of whether the negative thoughts and feelings are understandable or even justified. That is besides the point. The point is that it is I who now carry around the negative thoughts and feelings, that repeat themselves in a "crazy mind" tape loop in my head, just as the suffering of the injured foot persists until it is dealt with. It is I who am suffering, and so I must somehow overcome and lose the negative thoughts and feelings.

But notice that that discussion is from the point of view of the innocent. Today I want to think from the point of view of the guilty. And so we can see a potential danger if we misunderstand Buddhist teaching: granting that it is possible to be guilty, which I take to be a plain fact, we do not want to become so proficient at clearing the mind of negative thoughts and feelings that we lose our conscience altogether. That would be a grave misunderstanding of both Buddhism and Taoism. But at the same time it achieves nothing for the guilty person to be masochistic: to say to their self, "Yes I deserve these negative thoughts and feelings - I deserve to suffer." That by itself only makes the world worse, not better.

For ourselves, we can learn from our transgressions. We can meditate and become more mindful of the necessity of right action, right speech, and the other elements of the Path. There is nothing magical or mysterious about this. There is nothing mysterious or magical about Buddhism, at all; that is a very important point. For others we have wronged, I have only humble suggestions:

1) Atonement through concrete actions of restitution, when possible. Quotidian examples: returning stolen property, repairing or paying for damage, admitting lies and telling the truth. Replacing antagonistic actions with supportive actions.

2) Apology. But the act of apology is not without some risk of seduction by the ego. Perhaps further contact with you will only prolong or exacerbate the suffering of the person you have harmed. Perhaps your apology is a selfish act: perhaps it is only for your own sake that you want forgiveness. (Slanderers: the only person who does not need to hear from you is the person you have slandered. It is everyone else who you must speak to now.) Better to show contrition through deeds, and remember that non-action is often the best path. Assuming that you are the cure is just as egotistical as assuming that you are the disease.

This is not much to offer after bringing up such a promising topic, I realize. In the end I think that Buddhist practice is preventative, as I said at the beginning: cultivation of spiritual discipline and mindful character should aid us in avoiding bad action. And what would we call someone who did no harm? We can make up words. We'll never meet anyone like that.

Marshley's Project for Eastern Philosophy Class

2009-05-14T07:48:00.000-04:00

"Mind" is a Heterogenous Concept

2009-04-14T15:31:00.003-04:00

By "heterogenous concept" I mean one that turns out, under analysis, to refer to multiple, distinguishable things. All I mean by "analysis," that I am not using in any sort of technical manner, is thinking about the meaning of the term (semantics and metaphysics often come to the same thing). Examples of heterogenous concepts from outside of philosophy of mind are value terms like "ethics" or "beauty," or for that matter very many abstract nouns such as (opening the dictionary randomly) "resemblance" or "reservoir." Heterogenous concepts are common (I'm not sure I even like the word "concepts." To me it feels like I'm just thinking about words). We can understand the continuity of meaning between "That man's reservoir of good will" and "The city's reservoir of water," but if we are thinking metaphysically (in the sense of our ontology) about reservoirs the two uses are different enough that (I would say) it makes most sense to say "'Reservoir' is a heterogenous concept," meaning that it is a word that refers to multiple, distinguishable things.

Once we are alert to the possibility that one concept-word can turn out to refer to distinguishable things we can sometimes clear the smoke away a bit from philosophical arguments. For example ethical theorists (not the best ethical theorists, but quite a few ethical theorists) might see themselves as involved in some sort of partisan contest: are the rights theorists correct (or better or what have you), or are the consequentialists getting it right(er)? Or maybe virtue theory is preferable to both? But wait: people can be "ethical" at a civil, legal sort of level (respecting others' rights), and "ethical" at a phenomenal, qualitative sort of level (minimizing felt harm), and they can be "good" people in the sense of being an example of a well-realized person. And in fact real good people (that is, good people when they're not doing philosophy) use Kantian-style "golden rule" reasoning and Millian outcomes-based strategies and they make Aristotelean evaluations of themselves and others, all at the same time, because "ethics" turns out to be a heterogenous concept. The intentions of self-aware beings and the phenomenal experiences of conscious beings and the health or pathology of living beings are all different things, such that there turn out to be not so much differences of opinion among "ethical theorists" as there are changings of the subject.

"Mind" is a heterogenous concept. Specifically, when people use the word "mind" they are sometimes referring to (using these words in their philosophy of mind sense) the intentional (beliefs, desires, hopes, fears), which is about persons and sometimes to the phenomenal (pains, tastes, sensations, tingles), which is about bodies. Thus we can use the same strategy that I just used to try to sort out "ethical theory" to try to sort out "theory of mind." Operationalist theories (such as functionalism) are addressing the problem of intentionality while materialist theories are addressing the problem of phenomenology. And both approaches work in their respective applications. Thus we can cut the contemporary gordian knot of philosophy of mind. That's why I am calling this project The Mind/Body Problems, plural.

One more point, about why it has been so hard for so long for people to realize that "mind" presents us with (at least) two metaphysical problems, not one. (Gilbert Ryle got this point right.) That is because most cultures and thus most persons have deeply internalized the ontology of the soul: one body, one mind. The body indisputably is something, some one thing, a very fancy physical object. The grammar (as Wittgenstein would say) of the word "mind," suggesting as it does that it refers to some one, individuated thing, combined with the idea that the mind is something separate from the body, creates a strong intuition (a wrong one) that there is one metaphysical problem here. And that has led to a great deal of heat and not much light at all.

What Should We Be?

2009-03-12T08:21:00.005-04:00

Readers of this blog know my main interests lie in the area of contemporary philosophy of mind and metaphysics. However, I enjoy, through my teaching duties, the luxury of regularly studying any number of other topics. Spring semesters one of my regular courses is Contemporary Philosophy. This spring I decided to conduct a survey of the 19th and 20th centuries in "two movements," an effort to get to the bottom of the so-called "Continental/Analytic" distinction, a polarizing categorization towards which I am generally skeptical, and of which I warn my students off (and I do feel that anyone who comes on as a strong partisan one way or the other is probably a mediocre philosopher, definitely a mediocre reader). The course outline can be found two posts previous to this one.

I started the first "movement" (in the compositional sense) with Kant, moving through the German Idealists, Hegel (and Kierkegaard presented as a reaction to Hegel), Marx (who I believe straddles the two so-called traditions), Schopenhauer, Nietzsche, Freud, Husserl, Heidegger, Sartre, Merleau-Ponty, De Beauvoir, the "Critical Theory" of the Frankfurt School (Marcuse, Habermas), "Structuralism" (Foucault, Lacan), and finally, yesterday, Derrida. Now we will go back to the 18th century and start all over again with Hume, moving through a similar survey (this time composed almost entirely of English-language philosophers) through to the metaphysical revival of David Lewis and Alvin Plantinga.

So this week we are discussing and evaluating so-called Continental (I insist on the "so-called" when using either name). It was, I think, a very useful survey, illuminating a striking continuity of concerns and affirming the truism that there is "nothing new under the sun"; virtually the entire conversation called "Continental" philosophy follows in a thoroughly formulaic way from Kant and Hegel (I don't say that pejoratively).

What I want to discuss today (thinking about our classroom discussion tomorrow) is the question that emerged for my students in a persistent way starting around Nietzsche and Freud. (I argued that these two taken together represent the bridge from Romanticism to Modernism.) Even earlier Kierkegaard insists on the essential absurdity of our life-choices, and the real sense in which Schopenhauer is a "pessimist" is in his advice that we simply give up the existential struggle and find peace by sinking down into thinghood (the worst sin for existentialists like Nietzsche and Sartre). The question is: if so-called Continental philosophers have worked so hard to establish our fundamental freedom and to deconstruct our assumptions about our own natures, than what should a body do?

My student Kristian Rullan raised the question during the discussion of Sartre: if Sartre is right that consciousness is negation and nothing but negation, and that therefore (as Nietzsche also argued) we are entirely responsible for the most "essential" aspects of our own identities, then what is/would be the "existential person"? What would the existentialist have us do/be? My student Yasmin Zapata, chaffing a bit perhaps under the insistent subversiveness of de Beauvoir's existential feminism and the "permanent revolution" prescribed by modern Western Marxism, asked why it was necessarily so terrible, after all, to be a product and a creature of an historically conditioned and socially constructed culture? And it does appear that starting at the very beginning with Kant's distinction between a noumenal world-in-itself and a phenomenal world-of-experience, there is nothing less than a fetish in the so-called Continental tradition with the idea that "ordinary" people are trapped in an illusory world and that "enlightenment" would consist of a breaking through the wall of illusion into authenticity. And this fetish is still wholly present in the Althusserian notion of the "prison-house of language" that is the basis of Derrida's work. (I don't necessarily have anything against fetishes, by the way!)

This is the basic question that we will be discussing in class tomorrow. I have two thoughts about it just now (and of course I have no agenda of defending or promoting so-called Continental). First, it is of the essence of existentialism (pardon the pun) that there is no prescription: there is precisely no Existential Man the way there was supposed to be, say, a Soviet Man (and indeed the Western Marxists reject the idea of a Socialist Man as well). Sartre's gift to us of an argument for freedom, whether it is effective or not, necessarily precludes any prescription as to what we ought to be (and before him Nietzsche wants us only to "go over and go under" the sickly essentializing of "human nature," and Heidegger defines thinking as moving towards what is not known and cannot be said). The existential version of feminism developed by de Beauvoir and explored by subsequent French psychoanalytic feminists such as Kristeva similarly rejects the conception of feminism as a mere power play between the given "masculine" and "feminine." All of psychoanalysis, for that matter, is properly understood as emancipatory rather than prescriptive. And Derrida claims to write on "the margin," outside of the logocentric tradition of "metaphysics," the function of deconstruction being entirely to throw us into the necessity of self-creation.

Speaking critically, I find all of this tradition to be something of a "prolegomena to some future act of self-creation": they all insist on the reality of choice and the virtue of authenticity above all, but one rarely sees them actually choosing anything. This is why I have some affection for Kierkegaard: he out of the whole group actually manages to digest and embrace the conclusion and makes a choice.
My second thought is this: Socrates tells us that human nature is to think about what it is that we believe to be true, and that philosophy is to state that belief as clearly and courageously as possible. Try as you might, he taunts his relativist antagonists in the Theatetus, your arguments will never free you from this human condition. In a way the so-called Continental tradition draws a similar moral: the permanent revolution, the overcoming and the going under, is otherwise known as living. It is nothing more or less than having a life, and when we cease to interrogate ourselves in this way we have ceased to be persons.

(Footnote: If you are moved by existentialist discussions of the nature of consciousness, try reading some Buddhism. It is a much older tradition that elaborates these ideas to a much deeper level.)

Darwin the Empiricist

2009-02-12T08:41:00.008-04:00

On the occasion of Darwin's 200th birthday, I'd like to put Darwin in his philosophical context. Most of the time we think of the empiricism of Anglophone philosophy as the doctrine that knowledge is gained through observation and experiment, an epistemological formulation that was stressed by the greatest empiricist, David Hume. But there is another important aspect to empiricism that is often overlooked, partly because empiricists themselves have tended to spurn the idea of metaphysics (Hume aimed to do away with metaphysics altogether, and the early 20th century "positivists" such as A. J. Ayer also explicitly embraced that program). Empiricism (using that label broadly: liberal Enlightenment thought, English-language philosophy since Hobbes) represents a revolution in systems dynamics: the model of transformative processes in nature, which is ultimately a cosmological topic. Explaining the persistence of the identity of a thing across changes to the properties of that thing was a basic issue for the Greeks. Heraclitus simply denied persistence, Parmenides simply denied change. The Platonic solution was to bifurcate the world into an eternally unchanging component (form) and a transient polymorphic component (matter). (And I'm not so sure whether this is all wrong, by the way.) Thus change was explained as the (metaphysically problematic) interaction of the earthly with the divine (to put it in neoplatonic Christian terms). This model persisted beyond the Christian era in the Rationalist tradition through Descartes and Spinoza to Kant and Hegel. I call this the "top-down" model: the particular states of affairs at the micro level are explained by appeal to a macro transcendental force (Platonic universals, the Christian personal God, Kant's noumenal rationality, Hegel's Absolute Spirit, etc.).
Modern empiricism's development of an alternative model (the "bottom-up" model) is, I think, one of the most important developments in the history of philosophy, perhaps the greatest revolution in thought since Plato's metaphysics. The idea is that complex systems organize themselves through the iteration of simple algorithms at the micro level. In Locke this was the organization of society through the repetition of consensual behavior of self-interested individuals (democracy). In Hume this was the organization of a system of knowledge through regularities of observation (science). The kinship between Enlightenment democracy and science cannot be overstressed. One of Darwin's principal influences was Adam Smith's Wealth of Nations, published in 1776. Smith argued that complex economies organized themselves through the iteration of exchanges between individuals. His economics is an example of an application of the law of effect: actions resulting in negative consequences tend to be extinguished, actions resulting in positive consequences tend to be reinforced (Note: I think that one of Daniel Dennett's best articles is "Why the Law of Effect Won't Go Away"). Of course this is also the basis of behaviorist and other operationalist approaches to psychology. It is also the premise of Pragmatism, a thoroughgoing empiricist development of a theory of truth. Darwin's theory of natural selection is another application of the law of effect.
What did Darwin "discover," or what "theory" did Darwin develop? He pointed out that a proof in mathematical logic applies to all transformative processes in nature: given a set of replicators, the members of that set will have an average probability of reproductive success. That goes for conspecific breeding animals, flea market swaps and jokes. Any individual member with an above-average probability will tend to have more descendants in the next generation. That's not circular reasoning, because it leaves open the question of the reasons for the above-average probability. Selection of the fittest (most adaptive) from a variegated set. This is a proof that can be formalized. It's logically valid, which is not the same thing as empirically true. That is, it's not the kind of argument that can even potentially be false. Darwin did not develop a "theory." He simply pointed out the indubitable operation of a homely truth about the world, the law of effect, and in doing so he is coming straight out of the Scottish Enlightenment thought of Hume and Smith.
One more point: the law of effect operates on all levels. That is, genes, actions, beliefs, species, tribes, nations, come-on lines, ecosystems and all manner of replicating things, biological, cultural, and otherwise, come under this principle. Thus group selection and indeed selection at any level of organization whatever occurs, as Darwin himself recognized (for example in his discussion of the altruistic warriors of Tierra del Fuego). Thus the "selfish gene" doctrine of Dawkins is false. Not a question of science, it is a question of logic.
Happy birthday Charlie!

Teaching Contemporary Philosophy and the Continental/Analytic Distinction

2009-02-10T09:57:00.009-04:00

Every spring I teach the Contemporary Philosophy course that concludes our four-part history sequence (Ancient, Medieval, Early Modern, Contemporary) here at UPR/M. I've been struggling with it for a couple of years, having trouble finding a text, organizing a coherent narrative and so on. Two big problems are 1) if "Contemporary" is philosophy since Kant, or since 1800, there's just too much to cover, and 2) modern philosophy diverges and branches into several different narratives; the question emerges as to what "philosophy" even is. Adding to my frustration was my conviction that the distinction between "Analytic" and "Continental" was overstated, divisive and misleading (and further complications such as doubts about whether anything like "Analytic" philosophy really exists any more. The Spanish-speaking academics around me, with all due respect, simply use the blanket term "positivism" and haven't paid any attention since, say, A. J. Ayer). I try to get my students to see the reductive limitations of dividing things up ideologically between "Rationalist" and "Empiricist" or "Continental" and "Analytic." This taxonomy mostly just closes minds I think. Still and all, I have some very bright students here and some of them are curious enough to ask me to explain what "Analytic" philosophy is.
This semester I have developed a curriculum that covers the 19th and 20th centuries in "two movements," with the goal of uncovering and examining the roots of what I call "so-called Continental" and "so-called Analytic." What is happening for me (a good professor is always Student #1 in the class) is that I'm seeing that there is indeed a fundamental parting of the ways, and it does indeed have its roots in the arguments of Hume and Kant. I know that to some this will seem like a banality, perhaps it is, but the project here is to introduce, explain and interpret both of these strains. The main distinction textually speaking is between German-language philosophy and English-language philosophy, with an appreciation of the achievement of French-language philosophers of commuting between the two. Many important philosophers and topics are left out, but this is due to the fact that this is the outline of a one-semester class, after all, and we're blazing along as it is. Also the material at the very end reflects my own interest in philosophy of mind; there are any number of other directions one could take for the late 20th century.
Here is my outline of this semester's Contemporary Philosophy course:

THE HISTORY OF 19TH AND 20TH CENTURY EUROPEAN PHILOSOPHY, IN TWO MOVEMENTS
Anderson Brown, Contemporary Philosophy, Spring 2009

I. So-called “Continental”: From German Idealism to Deconstruction

A. Immanuel Kant (1724-1804), Critique of Pure Reason, 1781-1787

B. German Idealism: J. G. Fichte (1762-1814); G. W. F. Hegel (1770-1831), Phenomenology of Spirit, 1807; Friedrich Schelling (1775-1854)

C. The Metaphysics of Politics: Hegel, Karl Marx (1818-1883), Economic and Philosophic Manuscripts of 1848; Friedrich Engels (1820-1895)

D. Arthur Schopenhauer (1788-1860), The World as Will and Representation, 1819-1844

E. The Invention of the Unconscious: Friedrich Nietzsche (1844-1900), Thus Spoke Zarathustra, 1883, Beyond Good and Evil, 1886; Sigmund Freud (1856-1939)

F. Phenomenology and Existentialism, The Germans: Edmund Husserl (1859-1938); Martin Heidegger (1889-1976), Being and Time, 1927

G. Phenomenology and Existentialism, The French: Jean-Paul Sartre (1905-1980), Being and Nothingness, 1943; Maurice Merleau-Ponty (1908-1961), Phenomenology of Perception, 1945; Simone de Beauvoir (1908-1986), The Second Sex, 1949

H. Critical Theory (The Frankfurt School): Herbert Marcuse (1898-1979), One-Dimensional Man, 1964; Jurgen Habermas (b. 1929), Knowledge and Human Interests, 1968

I. Structuralism: Michel Foucault (1926-1984), Archaeology of Knowledge, 1969; Jacques Lacan (1901-1981)

J. Deconstruction: Jacques Derrida (1930-2004), Of Grammatology, 1967

II. So-called “Analytic”: From Enlightenment Liberalism to the New Metaphysics

A. David Hume (1711-1776), A Treatise of Human Nature, 1739

B. The Law of Effect: Adam Smith (1723-1790), The Wealth of Nations, 1776

C. The Revolution in Systems Dynamics: Charles Darwin (1809-1882), The Origin of Species, 1859

D. Empiricist Ethical Theory: John Stuart Mill (1806-1873), Utilitarianism, 1861

E. The Pragmatists: Charles Sanders Peirce (1839-1914); William James (1842-1910), The Will to Believe, 1897; John Dewey (1859-1952)

F. The New Logic: Gottlob Frege (1848-1925); Alfred North Whitehead (1861-1947); Bertrand Russell (1872-1970), Principia Mathematica, 1910-1913

G. Logical Positivism: A. J. Ayer (1910-1989), Language, Truth and Logic, 1936

H. “Ordinary Language” Philosophy: J. L. Austin (1911-1960), Sense and sensibilia, 1959

I. Ludwig Wittgenstein (1889-1951), Tractatus Logico-Philosophicus, 1921, Philosophical Investigations, 1951

J. The New Philosophy of Mind: Hilary Putnam (b. 1926); John Searle (b. 1932), Minds, Brains and Science, 1984; Jerry Fodor (b. 1935), The Language of Thought, 1975; Daniel Dennett (b. 1942)

K. The New Metaphysics: Alvin Plantinga (b. 1932); David Lewis (1941-2001), On the Plurality of Worlds, 1986

Metaphysics, Semantics, and the Mind/Body Problem

2009-01-28T07:11:00.004-04:00

We can bring the idea of "metaphysics" down to earth by relating it to the idea of "semantics." If metaphysics is the study of what exists (in our time this is essentially the confrontation with materialism), semantics is the study of the meaning of words. If my friend is talking about "angels" I can think about whether such putative entities exist but, more subtly, I can ask what he means, or aims to communicate, by this word. Thus even if we tacitly accept (as many of our contemporaries do) a physicalist axiom (metaphysically speaking), that doesn't mean that there is no longer anything to discuss about the mind/body problem. In fact the semantic analysis of intentional and phenomenal terms (the psychological vocabulary) remains an open and even a pressing issue, even for the thoroughly modern physicalist.
For Descartes the mind/body problem was essentially an interaction problem. He did not question (that is, he had his reasons for accepting) the existence of both physical substance and mental "substance." The metaphysical problem as he saw it was about causal relations between them. Thus there was one sort of entity, body, and another, mind. But if we don't accept Descartes' underlying ontology the problem is altogether different. Specifically we needn't see "mind" as referring to one thing or having one meaning (this was Ryle's enduring point expressed in the very title The Concept of Mind). Once we see this we can take a crucial step: we can distinguish the intentional psychological vocabulary ("belief," "desire," etc) from the phenomenal psychological vocabulary ("pain," "sensation," etc). We can see that there are (at least) two metaphysical (semantic) problems here, not one.
To apply this, I think that the eclipse of reductive materialism in favor of functionalism on the grounds that intentional states superevene on (are multiply realizable in) physical states is justifiable (there is indeed a problem for reductive materialism here), but that doesn't preclude identity theory as applied to phenomenal states. And that insight opens up a whole new discussion in philosophy of mind.

Externalist Non-Reductive Materialism vs. Internalist Non-Reductive Materialism

2008-12-04T15:27:00.003-04:00

Non-reductive materialism is the view that mental states are multiply realizable. As humans, dolphins, Martians and androids might all come under the intentional predicate of "believing that the fish are in the bucket," say, it follows that type-to-type identity fails: the type of intentional state we call "believing that the fish are in the bucket" cannot be identified with any specific type of neural state (some human neural state for example). The "materialism" part of non-reductive materialism is token-to-token identity: every token intentional state is identical, on this view, to some token physical state. This is a basic premise of functionalism: functional descriptions must replace physical descriptions because functions are multiply realizable (or, functions supervene on physical systems).
We can think about the difference between externalist non-reductive materialism and internalist non-reductive materialism. The internalist thinks that intentional predicates pick out states that are in the head (or body anyway, if you wish to be more careful). To say that "He believes that the fish are in the bucket" is to say that there is a particular state of affairs in his head, presumably some neural one. On the internalist view, what is multiply realizable is this internal process that in humans is essentially neural. We can see that this view is closely tied to representational models of nervous system function: if believing that the fish are in the bucket is a state of affairs (or a process) that is happening entirely in the subject's head this may entail that "fish," "the bucket" and so forth are somehow (images? formal symbols?) represented in the head.
But there is also the option of externalist non-reductive materialism. On this view intentional predicates apply to whole, embodied persons interacting with their environment. This looks to me to be right. Brains don't think any more than stomachs eat lunch: stomachs digest, persons eat lunch. Persons think, brains do...what? Seeing this question feels like progress. The externalist view is that mental predicates do not refer to brain states. That insight is interesting on the mental side, but it also washes back onto the question of what it is that neural processes in fact accomplish.

Does "Naturalism" Mean Anything?

2008-11-26T04:51:00.002-04:00

Yesterday I made a presentation of my work on the mind/body problem on the occasion of inaugurating a student philosophy colloquium here at UPR/M. It turned out to be a pretty good event and thoughtful responses from some good students (and from some generous faculty members) gave me much to think about.
A book-length project is hard to set up for an hour or so of informal discussion. One can't expect an audience of undergraduates (or of faculty with dissimilar interests for that matter) to simply jump in. It would be easy to spend an hour just lecturing on the nature and scope of "metaphysics." So I did something at the beginning that is fairly standard for me in class: I said that my interest in the metaphysics of the mind/body problem was motivated by an interest in "naturalizing psychology." All I want to do with this phrase is indicate something about my attitude; "I don't do ghosts and goblins, I don't do angels and demons," is something else that I say (and said yesterday). But a smart sociology major fixed on this issue of naturalism and the graybeards picked up on it and collectively they convinced me that this little bit of introductory business is too glib as it stands. Two things:
1) a) I don't actually know (news flash) all about the metaphysics of the universe. I have a programmatic "antihumanism": I do insist that humans are not exceptional, or miraculous, or otherwise different from the rest of nature. Resistance to this basic (metaphysical) fact (if it is a fact), for example among the linguists, hampers on my view progress in cognitive science and psychology. Nature might be as miraculous, mysterious and magical as you like, my claim is just that whatever nature in general is like, humans are like that.
b) I think that there are two claims that are both common and false in discussions about the mind/body problem: 1. That mental processes involve representations; that there is mental content. 2. That physical descriptions and explanations do not convey the quality of individual experiences ("qualia"), and therefore an autonomous "phenomenology" will always coexist with physical psychology (I disagree with the part after the "therefore").
I think an important thing I learned yesterday is that in my introductory exposition I should maybe limit myself to those more specific claims. Otherwise I commit myself to defending more than I am able, or care to, defend: I'm not writing a book an "naturalism." I don't even know what that means, it's way too broad of a concept and sweeping of a claim. A tricky thing in philosophy is not to toss out some bone that is not really essential to the argument, that people will then pick up and worry, at the expense of the intended project. Once I received the comments from two blind reviewers who had read an article of mine: both reviewers complained that I had not defined "behaviorism" properly, and both offered their own definitions, mutually contradictory. Moral of the story? Don't define it! We are too much ships passing in the night. I think that I should definitely not have a full-blown section advocating "metaphysical naturalism" in the introduction. My aims are much more specific.
2) Nonetheless there is a rich discussion to be had. It's got to mean something, after all, to say that one is a materialist. I think that that means that the metaphysical assertion has to have some sort of epistemological implication. Like Aristotle, like the functionalists, I eventually want to help myself to some sort of "nonreductive materialism," but I wonder if we are entitled to help ourselves to that. Aristotle thought that he had taken Plato's insight into the distinction between form and matter and "naturalized" it with his claim that substance, the unity of form and matter, was primary being. Nonreductive materialism: every token of form is material. Is that satisfactory? (As to that, some functionalists point out that functionalism need not commit itself to a materialist ontology. That might be fair enough, but there is still a question as to whether or not a materialist ontology is correct.)

How Do Lists Work?

2008-10-28T12:11:00.002-04:00

If I were at the supermarket and I had to remember what to get, one thing that could happen would be that I got out of my pocket a list that G. had written out and given me for this purpose. If you asked me how I remembered and I told you about the list in my pocket, that would be genuinely explanatory: that would explain how I remembered the items. But if we try to use such an explanation for cognitive operations inside the head, this kind of explanation will not be explanatory. If the model claims that the brain has already stored information and "remembering" is a matter of accessing this database then the "explanation" assumes what needs to be explained, that is, how the nervous system "stores information" in the first place. In the case of the piece of paper with writing on it in my pocket this is not mysterious. Similarly with supposed explanations of dreaming, hallucinating, but most basically with theories of perception itself. As soon as perceiving something is modeled as forming a representation the problem is full-blown.
In class this week a student asked, "But then how do you explain perception, memory etc. if not with reference to mental content?" The point is that the concept of "mental content" itself fails to be explanatory, thus the question is loaded. It does no good to say that I remember my friend's face by mentally "inspecting" a mental "picture" of my friend.

The Two Problems of Intentionality

2008-10-19T15:37:00.002-04:00

To understand the metaphysics of the mind/body relationship we have to see that there is not one metaphysical problem, there are several (and this also requires us to recognize that "mind" is a heterogenous concept, referring to several different things at once). The problem of phenomenal "properties" requires, I think, a metaphysical solution that is completely different from how we address the problem of intentional "properties" (ultimately I don't think there are any mental properties, hence the scare quotes). Intentionality itself breaks down further into two distinct metaphysical problems.
The first problem is the problem of meaning, that is, the question of how a physical thing can mean anything, be a symbol, refer to something else. There is a keyboard, a mouse, two pads of paper and a cellphone on the desk in front of me (in class I usually hold up my piece of chalk, Luddite that I am). None of them means anything. Physical objects don't mean anything: that's not a property that they have. Books don't mean anything either: readers of natural languages look at the printed marks (letters, words, sentences) on the pages and attribute meanings to them via conventional rules understood by readers of the language. But it has appeared to many over the centuries that mental states do genuinely have this intentional property of meaning, or referring to, something other than themselves. Think of a rhinocerous, the story goes: now your mental state is about a rhinocerous (the little picture in your mind's eye is a picture of a rhinocerous). But wait: if we opened up your head and poked around in there, we wouldn't find any little picture (or word). We'd just find brains, neurons, biomush of one sort or another, with some electrochemical humming and buzzing going on. Brains (human bodies) are just physical things, like pieces of chalk and notepads, and those sorts of things don't mean anything. But mental states do. That's the first problem of intentionality. (Teaser: yes, I have solutions to propose to these metaphysical problems, but just now I'm just trying to get more clear on sorting them out).
The other problem of intentionality doesn't get as much attention, although it is the main problem according to Plato, and it is key to understanding Descartes, Chomsky and Davidson among others. That is the problem that we often see picked out in our contemporary literature with the phrase "the rationality assumption." When we predicate intentional states to persons we not only attribute mental contents to them (that's the first problem again), but we also (must) make an assumption that they are possessed of some minimal degree of rationality: our attribution of such-and-such beliefs and such-and-such desires is only useful in predicting and explaining behavior if the subject connects these contents through a system of logical relations. He believes that the drinking fountain is down the hall, he desires a drink of water: these two intentional states only link up assuming he has a minimal capacity for reason. And this appears metaphysically puzzling as there do not appear to be any logical relations between (after all, contingent) physical states, including brain states. Thus Davidson argues that there can be no psychophysical laws linking any given brain state to any given intentional state, Plato argues that the capacity for logic possessed by rational beings frees them from the determinations of physical laws, and Chomsky argues that the ability to formalize mathematics and logic represents a radical break between rational beings and non-linguistic beings whose behaviors can be explained using learning models (behaviorism) and adaptationist explanations (evolutionary psychology). In fact all rationalists develop some variation on this theme.
As I said, I do have metaphysical solutions to offer to these problems, but right now I have to go home to play with my three-year-old and to bake a quiche with the chicken left over from last night. Subscribe!

Against the Cynical Reading of the Early Moderns

2008-10-12T09:00:00.005-04:00

There is what I think of as the Cynical Reading of Early Modern philosophers, notably Descartes and Spinoza but the claim extends to every 17th and 18th century philosopher who discusses God (with the exception of Berkeley who is clearly in earnest, and whose reasoning for the existence of God is quite original and unique, whatever its other merits). The Cynical Reading claims that Early Modern philosophers are closet secularists who affirm the existence of God so as to not get into trouble with the authorities and, more importantly, to make the new science of nature palatable for the popular culture. For example Spinoza, on this interpretation, identifies God with nature in order that we can simply get on with studying nature, the "intellectual love of God" (similarly Newton famously remarked that in explicating the mathematical constants of nature he was "revealing the face of God"), much as Berkeley, concluding that Locke's account of "extended substance" vs. perceptions was hopelessly muddled, proposed that we simply ditch extended substance altogether and start over with perceptions only.
I don't think that the Cynical Reading is coherent. Even Leibniz, who did in fact have a public philosophy and a gnostic philosophy, continues to discuss God in the gnostic writings. Newton, for that matter, hid the extent of his religious convictions, which were intense, rather than the other way around. Even Hobbes, who has an austere materialist metaphysics of "matter in motion," devotes the second part of Leviathan to a (to my eye very murky) discussion of religion. The only Early Modern who is patently and outspokenly atheist is Hume but he appears to be quite sincere in this after all. And when Nietzsche dismisses Kant's "noumenal" world as simply a place to store God now that He is banished from the natural ("phenomenal") world Nietzsche is accusing Kant of fooling himself, not us.
I think that there is a more interesting response to the Cynical Reading than just appealing to textual evidence that the Early Moderns were sincere. The problem with the Cynical Reading of the Early Moderns is that it requires the proposition that philosophers of the 17th and 18th centuries had already absorbed the secularist implications of the new science, and sat down to write their works after some prior process of coming to understanding. And when did this difficult process occur, since we have no record of it? No, these people may be investing the term "God" with some technical meanings (Spinoza, Leibniz), but when we read these texts we are looking at the process of moving from the old faith-based epistemology to the new science-based epistemology. This is a transitional period (part of what accounts for the incredible philosophical richness of the relatively short historical period from Descartes' Discourse to Kant's Critique), and what we see in these discussions of God is the process itself unfolding. The Early Moderns are both theologians and naturalists, these conceptual systems cohabiting the same heads, an historical condition fraught with difficulty, and that very difficulty is driving the process of philosophical creation. The Cynical Reading's worst fault is its mediocrity: a facile reading that avoids the real issues.