Well, that is annoying. The trouble is that startling identity claims have a way of boomeranging. The Vedantist says “You are God!” hoping to shock his listener out of his egotism. The shallow listener thinks “Wow, I am God!” and his egotism is only reinforced. He puts the accent on the “I” rather than on “God.” And why not, if he and God really are identical?
Something similar can be said of the claim that the mind is identical to the brain. This is usually interpreted as an assertion of materialist reductionism. But why not interpret it instead as an assertion of idealist reductionism, a claim to the effect that a certain purportedly material object, the brain, is really mental? Indeed, the later Bertrand Russell held something like this view; or rather, he held that it is the sense data we encounter in introspection (“qualia” we’d say today) that are the fundamental reality, and that minds and material objects are constructs out of this purportedly “neutral” stuff. Russell took sense data to be “neutral” – that is to say, of themselves neither mental nor material – rather than mental (as they are usually regarded), because he thought they could intelligibly be held to exist unsensed by any mind. Some contemporary followers of Russell (such as Michael Lockwood) follow this line. But others who have toyed with Russellian views (such as Galen Strawson and David Chalmers) concede that sense data really are inherently mental rather than neutral, so that the version of Russell’s views that they have developed is not a kind of “neutral monism” (as Russell sometimes called his view) but rather a variant of idealism or panpsychism. “Matter,” on their view, is really mental in its intrinsic nature. And if you are going to take seriously an identification of mind and matter in the first place, why not “reduce” in that direction?
Functionalism claims that the mind is not identical to the brain per se, but rather that it is to be identified with a certain kind of causal structure, which might be realized in the brain but could also in principle be realized in material systems other than the brain (in an android, say, or in an extraterrestrial with a material composition radically different from ours). Under the influence of Russell’s views, my younger self toyed with the idea of reversing this functionalist identification, of doing to functionalism what Russell did to the mind-brain identity theory. Instead of reducing mind to a certain kind of causal structure, I proposed that the reduction should go the other way. It is not that the mental phenomena we know from introspection are really “nothing but” a certain kind of causal structure of the sort we observe in the external world; it is rather (so the view went) that the kind of causal structure in question turns out to be inherently mental, that introspection reveals to us something about the intrinsic nature of causation that perception of the external world does not. I called the view “Russellian functionalism,” or, alternatively, “Hayekian functionalism,” since the view occurred to me as I was first studying F. A. Hayek’s neglected book The Sensory Order, which combines ideas similar to Russell’s with a kind of functionalism (though Hayek himself did not state his position in quite the way I did). I defended the view in print in my 2001 article “Qualia: Irreducibly Subjective But Not Intrinsic.”
I haven’t held this view for a long time. I now think it is bizarre – indeed, I realized that it was bizarre even at the time (I just thought we had to accept it anyway), and others with whom I then discussed it certainly thought, quite rightly, that it was not only bizarre but difficult even to understand. But I also think that it is no more bizarre or difficult to understand than garden-variety functionalism is (just as idealism is no more bizarre or difficult to understand than materialism is – if you think otherwise, I submit that that reflects your historical circumstances more than it does anything philosophically substantial). To assert that to be in pain is nothing more than to be in a state specified by the machine table of a Turing machine (or however one spells out one’s functionalism) should really strike us as quite unintelligible, because it is unintelligible. You might as well say that to be in pain is to be divisible by 3, or that to be in pain is to be a list of the ingredients for a jelly donut. Like all reductionist claims, it is really only intelligible as a roundabout way of asserting a kind of eliminativism: “’Pain’ as common sense understands it doesn’t exist at all; all that is really going on is what is described by the machine table.” In that case, though, we have a claim that is manifestly false. And, when the eliminativist line is taken toward intentionality – that is to say, when it is claimed that there is no such thing as a belief, or an assertion, or as something being “about” or “directed at” something beyond itself in any way at all – we have a claim that is incoherent. (Keith Yandell has a useful discussion of Advaita Vedānta as implying a kind of eliminativism.)
As Aristotle or Mr. A could tell you, A is A. Or as Joseph Butler famously put it, “Every thing is what it is and not another thing.” Very few people ever deny the law of identity outright. But it is violated implicitly all the time. Mind is not matter and matter is not mind. God is not me and I am not God. A stone is a stone, a tree is a tree, a dog is a dog, and a man is a man, and not a single one of them is “nothing but” a collection of particles (even if being composed of particles is a part of the correct story about their nature, as of course it is). To say all of that is not only to state the obvious but also to state (what is from an Aristotelian-Thomistic point of view) the metaphysically unavoidable. To deny these things is to lose one’s metaphysical moorings, and no one who does so should be surprised if he ends up somewhere other than where he hoped to go.