Response to Papineau
This is a letter I sent to the Times Literary Supplement in response to David Papineau's review of my bookThe Conscious Mind: In Search of a Fundamental Theory. The letter was published in their issue of August 2, 1996, in a somewhat mangled form that made a few points hard to follow.
How do we explain the existence of consciousness in a physical world? In his review of my book The Conscious Mind, David Papineau defends an odd form of materialism, holding that brain states are conscious states, and that is that. To one who asks for an explanation of this fact - why does being in a brain state feel any way at all? - Papineau insists that we unask the question. The identity between brain states and conscious states is not something to be further explained, but rather is a sort of explanatory primitive.
This seems to make consciousness more mysterious than ever, except that Papineau puts a positive spin on his views by holding that identities are not the sort of thing one explains. But this is false, or at least misleading. The only explanatorily primitive principles elsewhere in science are the fundamental laws of physics: from these (plus boundary conditions), all else follows. Someone possessing the concepts of "Samuel Clemens" and "Mark Twain" (to use Papineau's example) but ignorant of their identity could deduce that identity from a specification of the microphysical facts, for example. But Papineau concedes that the brain-mind link cannot be deduced from microphysics; so this link is explanatorily primitive in a much stronger sense.
I think that such explanatory primitiveness is the mark of a fundamental law of nature, and so (in my book) go on to investigate a "fundamental theory" of the mind-brain link, analogous to fundamental theories in physics. Papineau chooses to call the primitive relation an "identity" rather than a law, thus saving materialism in letter if not in spirit. I suspect that many will find that the most important point has already been conceded; but in any case there are further technical reasons, discussed in the book, why this maneuver does not make sound philosophical sense.
In brief: Papineau's position commits him to a notion that I call "strong metaphysical necessity", in which there is little reason to believe (it is unlike any necessity found elsewhere in philosophy), and which suffers from all sorts of problems. He avoids this issue by misrepresentation and elision: he wrongly implies that my analysis assumes a "descriptive" view of reference, and he unaccountably ignores the treatment of strong metaphysical necessity, which is there to handle precisely his sort of "escape route". His further talk of "reference by simulation" and an "antipathetic fallacy" merely reiterates, rather than justifies, his commitment to explanatorily primitive identities and strong metaphysical necessities.
Technicalities aside, it is hard to see how Papineau's declaring the mind/brain relationship an "identity" gets him off the hook in providing a detailed theory of consciousness. We would still like a theory to predict just how various brain states will feel, whether it feels like anything to be a different system such as a computer, and so on (unless Papineau implausibly denies that there is a fact of the matter here). And as elsewhere in science, one would like to systematize and simplify the relevant principles as far as possible. The result might well look like the fundamental theories I recommend, whether one talks of identities or laws.
Papineau's critique of my positive views consists in the observation that I am committed to epiphenomenalism - another misrepresentation. Although I don't share Papineau's phobia toward this view, I discuss at length an interpretation that avoids both epiphenomenalism and Cartesian dualism. This is an adaptation of the Russellian idea, recently advocated by Michael Lockwood, that the intrinsic qualities of experience can play the role of the intrinsic qualities of matter, on which physics is silent. This idea turns out to fit nicely with the information-based theories sketched in the constructive half of the book (which Papineau skips entirely). I think the choice between ontologies here is still open, but there are plenty of interesting options.
It would be terrific if the problem of consciousness could be removed by a magic bullet as simple as Papineau's, and life would be a lot easier if every opponent's argument could be shoehorned into a familiar stereotype. But deep problems and real arguments have a habit of popping straight back up again.
Department of Philosophy
University of Arizona
Tucson, AZ 85721, USA.