Valerie Hardcastle is, of course, quite right to introduce the topic of evidence into the debate on naturalism. Unfortunately the examples she chooses (Einstein, Chalmers) fail to advance her case, the obvious point being that the Michelson-Morley experiment preceded special relativity theory by some eighteen years. In any case, who would claim that a hypothesis in chemistry is not naturalized until you've boiled up the test tubes? Obviously this is nonsense -- the hypothesis is simply unproven. What would happen if evidence came on to refute relativity -- would it cease to be a naturalistic theory? Of course not, it would just be wrong. Obviously the real distinction is whether a theory is open to empirical testing, rather than being carved out in stone on the descent from Mount Sinai.
Hardcastle denies the tag "natural" to Chalmers' theory for the same reason -- no evidence. But what evidence is there for any of the competing theories? Writers like Churchland, Crick and Koch have recently adopted a "wait and see" approach as to whether or not the answer to the hard problem will come out in the wash. So, on Hardcastle's own criteria, *all* current theorizing on consciousness is "pre-natural" (except in the eyes of those who deny the problem in the first place).
I think McGinn is clearly not a naturalist, since he claims that we can't have a theory of consciousness.
It's actually more a case of pessimism than non-naturalism. McGinn has reviewed the literature and found all the theories (including Chalmers') flawed on both logical and empirical grounds. And given his robust materialism he can't see how an answer could be possible. If a coherent naturalist explanation came up I'm sure McGinn would be delighted. But it hasn't, so the burden of proof is with his critics.
I'm quite sure that *all* of us would like to see theorising firmly grounded in empirical evidence, but what constitutes evidence in the field of consciousness studies? The reason most of us study consciousness is because of our subjective experience. Unfortunately the study of phenomenal experience has been largely ignored throughout this century, as a result of flaws in earlier crude attempts. But until consciousness as-such is studied in a methodical way we will have no progress in the field. Bernie Baars has made this point repeatedly and there is a fine paper on the topic by Varela forthcoming in JCS.
John Barresi:
now with an empirical solution to the 'binding problem' finally in our grasp, the possibility of 'unity of consciousness' in a spatial distributed brain, suddenly seems not nearly so incoherent.
Really? I must have nodded off for a moment -- no doubt this will be on the front cover of *Nature* this Friday and we can all read about it.
Keith Sutherland
keith@imprint.co.uk
I'm not sure what this flippant remark is supposed to mean. The point I was trying to make is that during the 17th and 18th century the notion of 'thinking matter' seemed impossible, partly because matter in the brain was distributed, and separable or 'discerpible'. By contrast, thinking was believed to be an property of a simple immaterial substance, in part because of its subjectively unified or 'indiscerpible' nature. Based on these 'conceptually distinct' properties, philosophers like the Cambridge Platonists, Samuel Clarke, and Abraham Tucker thought that it was impossible to give a 'naturalistic' account of consciousness (see Mijuskovic, 1974).
The central problem here was somehow to see that something divisible like matter, could sustain and account for something apparently indivisible like consciousness. Ultimately, this conceptual impossibility was resolved by 1) Conceiving that the 'unity of consciousness' might not be a simple unity but a constituted unity. Kant, I take it, provided this suggestion (partly in response to Hume who tried to argue for disunity without quite pulling it off). 2) Finding an empirical brain correlate of the apparent unity of consciousness. This, I take it, is the hope engendered by recent research on the 'binding problem'.
We may not yet have such a solution in hand, or 'on the front cover of Nature'. Yet the evidence of such researchers as Wolf Singer, who recently gave the annual Hebb lecture at Dalhousie, suggests that phase locked responses of neurons distributed throughout the cortex, may be the physical correlate of global constructed unity. Though this may not solve the 'hard' problem of consciousness, it might, at least, provide for the problem of unity at the 'easy' level. Hence, it is an answer to those 18th century theorists who thought that a 'discerpible' brain could not sustain 'indiscerpible' thought.
John Barresi
Reference:
Mijuskovic, B.L. (1974) The Achilles of Rational Arguments: The Simplicity, Unity, and Identity of Thought and Soul from the Campbridge Platonists to Kant: A Study in the History of an Argument. Hague: Martinus Nijoff.
John Barresi
JBARRESI@AC.DAL.CA
I've no problems with "hope", but my flippant remark was caused by your earlier less cautious:
But now with an empirical solution to the 'binding problem' finally *in our grasp* [my emph.]
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