The latter two issues are metaphysical (meaning not able to be decided by experiment) and belong to JCS-Online rather than Psyche-D.
Well Stan, I wish it was that simple and that we could keep our metaphysics and our science in separate pigeon-holes, but life isn't quite so neat and tidy. Consider the following from Valerie Hardcastle, who, as we all know, is a cognitive scientist not a sociologist:
Explanations are social creatures. They are designed for particular audiences asking particular questions wihin a particular historically determined framework . . . Materialists are trying to explain *to each other* [my emphasis] what consciousness is within current scientific frameworks . . . If you don't antecedently buy into this project, including its biases, history . . . then a naturalist's explanation probably won't satisfy you. (Hardcastle, 1996)
This brings her to the pessimistic conclusion that there is no common ground between naturalist explanation (as she portrays it) and mysterians and dualists like McGinn and Chalmers. However, both these authors would seek to position their own commentaries firmly within a naturalistic framework, so we do need to have a fresh look at what constitutes naturalistic explanation. But first a brief aside:
It's a pleasing observation on the multidisciplinary nature of consciousness studies that a technical symposium like the ASSC Newman thread should include no less than three commentaries by philosophers (Flanagan, Hardcastle, Metzinger), but are they playing by the same rules as the laboratory workers?
Thomas Metzinger, in the prologue to his commentary on Newman, castigates Harth, Libet, Greenfield and myself for failing to appreciate the distinction between "conceptual" and "empirical" theories. Whilst one might forgive philosophical amateurs like us for such a basic error, unfortunately some of Thomas's own peers seem to have made the same mistake. The symposium on his paper was inspired by a claim by Tom Clark that it provided precisely the sort of naturalistic theory that was needed for his functionalist dissolution of the hard problem. And Metzinger seems to have forgotten this distinction himself, referring to his own "empirical speculation" in the editorial introduction! (p. 388)
So what does it mean for an article which draws some 75% of its source citations from the empirical neurosciences to be "conceptual"? I have now read the piece five times and it seems pretty clear to me -- the article is an attempt to build a purely bottom-up, agent-free theory of everything from perceptual binding to the phenomenal self by reference to phase-locked thalamocortical oscillations. In my commentary I pointed out that this necessitated ignoring all of the clear evidence for top-down and reentrant processes and most of the psychology of perception, only to be told that the paper was only designed as a conceptual service for other philosophers. It does seem to me that if philosophers want to roll up their sleeves and pitch in with the rest of the brain science community then they have to accept the same rules of evidence as everyone else, rather than scurrying back to their philosophical ivory towers as soon as the going gets tough.
The contributions of philosophers to cognitive science are of two forms. First of all, we have the "so what" approach, which is intended to keep brain researchers on their toes and to point out when they are guilty of conceptual confusion or conflation. A good recent example here is Block (1996), in which he targeted Crick and Koch's recent Nature article where they conclude that striate cortex is not part of the neural correlate of consciousness. Block argued that C&K are guilty of a confusion between "phenomenal" and "access" consciousness. This sort of philosophical critique is an invaluable constraint on theory building in the brain sciences. This has to be contrasted with the attempt to build metaphysical theories. Dave Chalmers keeps the two quite separate in his book and no-one need be confused about when the critique ends and his own speculative attempt at theory-building begins.
This brings me back to Hardcastle's opening remarks on the social nature of explanation. She is quite candid that as far as she is concerned naturalism and materialism are synonymous. But my dictionary gives a slightly broader definition:
naturalism (philosophy): a scientific account of the world in terms of causes and natural forces.
OK, so this is a bit circular -- what do we mean by "natural":
based on the principles and findings of human reason rather than on revelation.
So on this definition, Chalmers' speculations (with all their panpsychic implications) clearly fall within the realms of naturalism, and the equation of naturalism with materialism is simply wrong.
What puzzles me most about this equation (and all the consequences of this in terms of bottom-up explanation) is that the reductive process ends up with physics and there is no agreement whatsoever over ontological issues in fundamental physics. So it's rather like constructing a high-rise building on quicksand, and perhaps this is one of the reasons why there is such a concerted effort in the congnitive sciences to curtail the process at the neuronal level. Materialism is just another metaphysical theory -- in fact, historically, its only really half a theory -- originating in a cartesian divide which now looks to be increasingly artificial. And the only way you can really defend materialism in consciousness studies is by recourse to that old book of Ryle's that Aaron keeps banging on about. Was I alone at Tucson in finding DD's metaphors and British Empire travellers' tales just a little bit past their sell-by date? Surely we've moved on since 1949.
One of the interesting things about consciousness studies is that it is no longer possible to separate science from metaphysics in the way Stan suggests.
P.S. Thomas M. also made a disparaging reference to Mike King's jcs- online thread on the "Krishnamurti Dog Paradox" (KDP). I would like to point out that, unlike Gary Cottrell's spoofs on Dognitive Science and Schroedinger's burlesque feline example, the KDP is a deeply serious meditation on the difference between animal and human consciousness.
The papers by Metzinger, Sutherland, Harth, Libet, Greenfield and King are all available through the jcs-online menu button below.
Block, N. (1996), Is V1 conscious and in what sense?, Toward a Science of Consciousness.
Hardcastle, V.G. (1996), The Why of Consciousness: A Non-Issue for Materialists, JCS, 3 (1), pp. 7-13.
Metzinger, T. (1995), Faster than Thought: Holism, Homogeneity and Temporal Coding, in Conscious Experience (Imprint Academic, Exeter).