Tuesday, October 28, 2008

How Do Lists Work?

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.

Sunday, October 19, 2008

The Two Problems of Intentionality

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!

Sunday, October 12, 2008

Against the Cynical Reading of the Early Moderns

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.

Friday, October 10, 2008

The Inverted Spectrum Argument

The "inverted spectrum argument" was developed as a critique of functionalism. Imagine someone whose color spectrum was inverted: where normal people saw red, this one saw blue, where blue, red. Such a person, raised among normal, English-speaking persons, would be functionally indistinguishable from normal persons: 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 their experience of seeing the blue surface of the bag was the same experience the rest of us have when we see a red surface, since they, like everyone else, would refer to such a surface as "blue." Since such a person 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.
This is, I think, the very same argument as the "zombie argument" made famous by David Chalmers: imagine a person who behaved exactly as a normal person does, but who has no conscious experience whatsoever. Again, there would be no way of knowing that one was interacting with a non-conscious "zombie." The arguments can be run using two imagined persons, or one person and a machine. Imagine that I have a wine-identifying device. I put a drop of wine in the device and it spins out the molecules in a centrifuge, and then identifies them using an on-board data base, and has a readout telling me that it is a merlot from such-and-such a vineyard, of such-and-such vintage etc. If I encountered a true wine afficionado I could match him identification for identification, but he would be using his familiarity with respective gustatory qualia whereas I would be using my device. Or imagine an android who was functionally identical to a person but non-conscious. "Inverted spectrum" and "zombie" are two variations of one argument, we can call this the "absent qualia argument." Typically this argument is presented as showing that functionalism (and behaviorism, and operationalist theories of mind in general) founders on the problem of phenomenal properties.
Wittgenstein, for one, noticed that in fact the absent qualia argument demonstrates just the opposite: since it is not even in principle possible for public language (the only kind of language there is, according to Wittgenstein) 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 discussion of the quality of private sensations. These are beyond the range of language.
Wittgenstein deploys the "private language argument" in two different ways. Regarding intentional mental states, he denies the possibility of mental content altogether: there can be no representation, symbolic, isomorphic, or otherwise, in the head. Regarding phenomenal mental states, he does not deny that experience has quality, only that these qualities can be picked out using language. While the problem of intentionality and the problem of phenomenology are, on my view, two distinct metaphysical problems, Wittgenstein can address them both because his thesis is in fact about language, and this thesis can be applied in any number of ways.