This piece in the New Scientist suggests that creationists and their sympathisers are seeking to open up a new front. They think that the apparent insolubility of the problem of qualia means that materialism is on the way out; in fact, that consciousness is ‘Darwinism’s grave’. Cartesian dualism is back with a vengeance. Oh boy: if there was one thing the qualia debate didn’t need, it was a large-scale theological intervention. Dan Dennett must be feeling rather the way Guy Crouchback felt when he heard about the Nazi-Soviet pact: the forces of darkness have drawn together and the enemy stands clear at last!
The suggested linkage between qualia and evolution seems tortuous. The first step, I suppose, assumes that dualism makes the problem of qualia easier to solve; then presumably we deduce that if dualism is true, it might as well be a dualism with spirits in (there are plenty of varieties without; in fact if I were to put down a list of the dualisms which seem to me most clear and plausible, I’m not sure that the Christian spirit variety would scrape into the Top Ten); then, that if there are spirits, there could well be God, and then that if there’s God he might as well take on the job of governing speciation. At least, that’s how I assume it goes. A key point seems to be the existence of some form of spiritual causation. Experiments are adduced in which the subjects were asked to change the pattern of their thoughts, which was then shown to correspond with change in the activity of their brain; this, it is claimed, shows that mind and brain are distinct. Unfortunately it palpably doesn’t; attempting to disprove the identity of mind and brain by citing a correlation between the activity of the two is, well, pretty silly. Of course the thing that draws all this together and makes it seem to make sense in the minds of its advocates is Christianity, or at any rate an old-fashioned, literalist kind of Christianity.
Anyway, I shall leave Darwinism to look after itself, but in a helpful spirit let me offer these new qualophiles two reasons why dualism is No Good.
The first, widely recognised, is that arranging linkages between the two worlds, or two kinds of stuff required by dualism, always proves impossible. In resurrecting ‘Cartesian dualism’ I don’t suppose the new qualophiles intend to restore the pineal gland to the role Descartes gave it as the unique locus of interaction between body and soul, but they will find that coming up with anything better is surprisingly difficult. There is a philosophical reason for this. If you have causal connections between your worlds – between spirits and matter, in this case – it becomes increasingly difficult to see why the second world should be regarded as truly separate at all, and your theory turns into a monism before your eyes. But if you don’t have causal connections, your second world becomes irrelevant and unknowable. The usual Christian approach to this problem is to go for a kind of Sunday-best causal connection, one that doesn’t show up in the everyday world, but lurks in special invisible places in the human brain. This was never a very attractive line of thinking and in spite of the quixotic efforts of those two distinguished knights, John Eccles and Karl Popper, it is less plausible now than ever before, and its credibility drains further with every advance in neurology.
The second problem, worse in my view, is that dualism doesn’t really help. The new qualophile case must be, I suppose, that our ineffable subjective experiences are experiences of the spirit, and that’s what gives them their vivid character. The problem of qualia is to define what it is in the experience of seeing red which is over and above the simple physical account; bingo! It’s the spirit. To put it another way, on this view zombies don’t have souls.
But why not? How does the intervention of a soul turn the ditchwater of physics into the glowing wine of qualia? It seems to me I could quite well imagine a person who had a fully functioning soul and yet had no real phenomenal experiences: or at any rate, it’s as easy to imagine that as an unsouled zombie in the same position. I think the new qualophiles might reply that my saying that shows I just haven’t grasped what a soul is. Indeed I haven’t, and I need them to explain how it works before I can see what advantage there is in their theory. If we’re going to solve the mystery of qualia by attributing it to ‘souls’, and then we declare ‘souls’ a mystery, why are we even bothering? But here, as elsewhere with theological arguments, it seems to be assumed that if we can get the question into the spiritual realm, the enquiry politely ceases and we avert our eyes.
It is, of course, the same thing over on the other front, where creationists typically offer criticism of evolutionary theory, but offer not so much as a sniff of a Theory of Creation. Perhaps in the end the whole dispute is not so much a clash between two rival theories as a dispute over whether we should have rational theories at all.