Chomsky on the mind-body problem

I am, to say the very least, not a fan of Noam Chomsky’s writings on politics and foreign policy. But his straightforwardly philosophical work is always interesting and important even when one disagrees with it. A case in point is his view of the traditional mind-body problem. The usual assumption is that we have a clear understanding of what matter is, and that the difficulty has to do with explaining how thoughts, sensations, and other mental phenomena relate to material processes in the nervous system. Are the former identical to or supervenient upon the latter? Various anti-materialist arguments purport to show that they cannot be either, which seems to entail some form of dualism. But in that case we face the interaction problem. In any event, the “body” side of the mind-body problem is usually taken to be unproblematic; it is mind that raises the puzzles, or so it is thought.

Chomsky rejects this assumption. In his view, “body” is as problematic as mind; so much so that we do not even have a clear idea of what the mind-body problem is. As he writes in Language and Problems of Knowledge: The Managua Lectures:

The mind-body problem can be posed sensibly only insofar as we have a definite conception of body. If we have no such definite and fixed conception, we cannot ask whether some phenomena fall beyond its range. The Cartesians offered a fairly definite conception of body in terms of their contact mechanics, which in many respects reflects commonsense understanding. Therefore they could sensibly formulate the mind-body problem… (p. 142)

[However] the Cartesian concept of body was refuted by seventeenth-century physics, particularly in the work of Isaac Newton, which laid the foundations for modern science. Newton demonstrated that the motions of the heavenly bodies could not be explained by the principles of Descartes’s contact mechanics, so that the Cartesian concept of body must be abandoned. (p. 143)

In other words, when we think of causation in the natural world as Descartes did – that is, as involving literal contact between two extended substances – then the way in which a thought or a sensation relate to a material object becomes mysterious. Certainly it cannot be right to think of a thought or sensation as making literal physical contact with the surface of the brain, or in any other way communicating motion in a “push-pull” way. But when we give up this crude model of causation, as Newton did, the source of the mystery disappears. At the same time, no systematic positive account of what matter as such is has ever really been put forward to replace Descartes’ conception. Hence, Chomsky continues:

There is no longer any definite conception of body. Rather, the material world is whatever we discover it to be, with whatever properties it must be assumed to have for the purposes of explanatory theory. Any intelligible theory that offers genuine explanations and that can be assimilated to the core notions of physics becomes part of the theory of the material world, part of our account of body. If we have such a theory in some domain, we seek to assimilate it to the core notions of physics, perhaps modifying these notions as we carry out this enterprise. (p. 144)

That is to say, we have in Chomsky’s view various worked-out, successful theories of different parts of the natural world, and we try to integrate these by assimilating them to “the core notions of physics,” but may end up altering those core notions if we need to in order to make the assimilation work. As a result, as Chomsky once put it to John Searle, “as soon as we come to understand anything, we call it ‘physical’” (quoted by Searle in The Rediscovery of the Mind, p. 25). But we have no conception of what is “physical” or “material” prior to and independently of this enterprise. And since the enterprise is not complete, “physical” and “material” have no fixed and determinate content; we simply apply them to whatever it is we happen at the moment to think we know how assimilate into the body of existing scientific theory. As a consequence:

The mind-body problem can therefore not even be formulated. The problem cannot be solved, because there is no clear way to state it. Unless someone proposes a definite concept of body, we cannot ask whether some phenomena exceed its bounds. (Language and Problems of Knowledge, p. 145)

Hence, while Chomsky is no dualist, neither does he embrace the standard alternatives: “There seems to be no coherent doctrine of materialism and metaphysical naturalism, no issue of eliminativism, no mind-body problem” (New Horizons in the Study of Language and Mind, p. 91). In short, if the problem has no clear content, neither do any of the solutions to it. Chomsky’s preferred approach, it seems, is just to carry on the task of developing and evaluating theories of various aspects of the mind and integrating them as one can into the existing body of scientific knowledge, letting the chips fall where they may vis-à-vis the definition of “physical” or “material.”

What should we make of this? Chomsky is, I think, absolutely right to emphasize that the concept of matter is no less problematic than that of mind, and that this entails that “materialism” and “physicalism” are far less determinate in content than their adherents typically suppose. (This is something Bertrand Russell also emphasized, as do later philosophers of mind influenced by him, such as Grover Maxwell, Michael Lockwood, Galen Strawson, and David Chalmers.) At the same time, I think it is clear that the concept of the “physical” or the “material” is not in fact as elastic as Chomsky’s remarks might imply, either in the thinking of most scientists or in that of philosophical naturalists.

It is true that the positive content of the notion is fairly indeterminate, subject to fluctuation with every change in the physical sciences. But there is a core of negative content that is more or less fixed. That is to say, whatever matter turns out to be, there are certain features that modern philosophers, and scientists in their philosophical moments, tend to refuse ever to attribute to it.

For at least some of them, this would seem to include sensory qualities like color, odor, taste, sound, and the like as common sense understands them. For the mechanistic revolution Chomsky alludes to was not merely, and indeed not even essentially, committed to the idea that material causation involves literal contact. It was also and more lastingly committed to some variant or other of a “primary/secondary” quality distinction on which there is nothing in the material world that “resembles” our “ideas” of the sensory qualities mentioned (as Locke would put it). If we want to redefine the “red” of a fire engine in terms of how its surface reflects photons at certain wavelengths, we can say that the fire engine is red. But if by “red” we mean the way red “looks” to us when we perceive it, then nothing like that exists in the fire engine, which is (if we think of color in these commonsense terms) intrinsically “colorless.” And so on for sounds, tastes, and all the rest. Color, odor, taste, sound, and the like – again, as common sense understands them (rather than as redefined for purposes of physics) – are reinterpreted by mechanism as projections of the mind, existing only in consciousness. This is the origin of the “qualia problem,” and the puzzle now becomes how to relate these “qualia” or “phenomenal properties” to the intrinsically colorless, odorless, tasteless particles that make up the brain just as much as they do external material objects.

Now if one insists on denying these sensory qualities to matter, then it seems clear that we do have a clear enough conception of “body” to generate a mind-body problem. More than that, we have a conception that clearly implies that the mind (in which alone these qualities exist) cannot be something material or bodily – that, at any rate, is the lesson drawn by early modern thinkers like Cudworth and Malebranche, and by contemporary writers like Richard Swinburne, who take the “mechanistic” conception of matter itself to entail dualism. (I have discussed this issue before in several places, e.g. here, here, and in The Last Superstition.)

A naturalist could, however, decide to reincorporate the sensory qualities into the material world by conceiving of them as the intrinsic properties of matter, which “flesh out” the abstract mathematical structure described by physics. And this is precisely the move made by the writers influenced by Russell whom I mentioned above – Maxwell, Lockwood, Strawson, and Chalmers. To be sure, the resulting position is hardly “materialist” or “physicalist” as those terms are usually understood; some of these writers describe it instead as neutral monist, or panpsychist, or even as a variety of dualism. But they also tend to regard it as nevertheless consistent with a kind of naturalism, even if what is allowed to count as “natural” is thereby expanded considerably. (An exchange between Strawson and Chomsky can be found in Louise Antony and Norbert Hornstein, eds., Chomsky and His Critics.)

There is, however, another, more fundamental and indeed absolutely “non-negotiable” component of the mechanistic picture of the world inherited from the early modern philosophers, one well-known to regular readers of this blog: the rejection of Aristotelian formal and final causes. As I have argued in many places (such as in this recent post, as well as in The Last Superstition and Aquinas), this is the surviving and definitive element of the mechanistic revolution, and the one which naturalists seem to take, either explicitly or implicitly, to be crucial to their position. Whatever else the physical world may turn out to be like, and whatever alterations might be made to scientific practice, the mechanist, and the naturalist, are committed to the view that there is no such thing as goal-directedness or teleology intrinsic to the natural world, and that proper scientific procedure ought never to posit such immanent teleology. (See the quotes in the post just linked to for examples of philosophers who endorse this conception of science.)

If this is correct, then we once again have a conception of matter, albeit a negative one, which is determinate enough to generate a mind-body problem. If nothing in the material world inherently points beyond itself as to an end or final cause, then it is hard to see how that aspect of the mind philosophers call intentionality – the way that a thought “points to,” is “about,” or is “directed at” something beyond itself (such as the way your thought about the Eiffel tower is “about” or “directed at” the Eiffel tower) – can possibly be given a “naturalistic” explanation. As I have argued in several places (e.g. here) a dualism of intentional phenomena and material phenomena seems unavoidable given a mechanistic conception of nature, even if the Russellian naturalist can avoid a dualism of qualitative phenomena and material phenomena by expanding his conception of the “natural” (though even that is not a sure thing).

As Jerry Fodor puts it in Psychosemantics: The Problem of Meaning in the Philosophy of Mind:

I suppose that sooner or later the physicists will complete the catalog 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. It’s hard to see, in face of this consideration, how one can be a Realist about intentionality without also being, to some extent or other, a Reductionist. If the semantic and the intentional are real properties of things, it must be in virtue of their identity with (or maybe of their supervenience on?) properties that are themselves neither intentional nor semantic. If aboutness is real, it must be really something else. (p. 97)

Of course, Fodor’s “Reductionism” is not really the only option. One could combine Realism about intentionality with dualism instead; or with idealism; or with Aristotelian hylemorphism. But the last of these positions would indeed be ruled out if one agrees with Fodor about what the physicists’ ultimate catalog must look like, and the other two options would certainly be incompatible with at least most naturalists’ understanding of “naturalism.” In any event, the passage illustrates the point that contemporary philosophers do have a determinate enough conception of matter (albeit a negative one) to generate a mind-body problem: Fodor’s point is that given the conception of the physical to which he and like-minded philosophers are committed, intentionality becomes philosophically problematic. The passage illustrates also that the naturalist seems bound at the end of the day to deny the existence of intentionality given his conception of matter. For to say that “if aboutness is real, it must be really something else” is just a cute way of saying that aboutness is not real, and must be replaced in our ontology by some physicalistically “respectable” ersatz. As Searle has complained (e.g. in the book cited above), materialist “reductions” of this or that mental phenomenon never really succeed in “reducing” it at all, but either change the subject or implicitly deny the existence of the phenomenon. Reductionist versions of materialism are really just disguised forms of eliminative materialism.

That is a big topic, but suffice it for now to emphasize two points. First, while Chomsky is right to say that modern philosophers’ conception of “matter” or “the physical” is far less determinate than they often suppose, it is in fact determinate enough to generate a real mind-body problem. Second, the mechanistic assumptions underlying this determination of their conception of matter are, contrary to what they (and Chomsky himself, I imagine) typically suppose, not “scientific” at all, but purely philosophical – and (as my regular readers know) in my view deeply mistaken.