Sunday, March 27, 2011

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

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.

Tuesday, March 15, 2011

Wittgenstein on Qualia

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.

Sunday, March 6, 2011

Hume on Qualia

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 outrĂ© 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.