There's a cheap debating trick which implies that if, say, science can't explain something, this must mean that some other discipline can. If scientists suspect that all aspects of the mind have a scientific explanation but they can't actually say what that explanation is yet, then of course it's open to you to doubt whether the explanation ever will be forthcoming. That's a perfectly reasonable doubt. But it's not legitimately open to you to substitute a word like soul, or spirit, as if that constituted an explanation. It is not an explanation, it's an evasion. It's just a name for that which we don't understand. The scientist may agree to use the word soul for that which we don't understand, but the scientist adds, "But we're working on it, and one day we hope we shall explain it." The dishonest trick is to use a word like soul or spirit as if it constituted an explanation.

Consciousness is still mysterious. And scientists, I think, all admit it. But we ought to remember that it's not that long ago that life itself was thought to be equally mysterious. I'm going to quote from a book, A Short History of Biology by Charles Singer, a reputable historian of science, published in 1931, where he says, about the gene,

". . . despite interpretations to the contrary, the theory of the gene is not a 'mechanist' theory. The gene is no more comprehensible as a chemical or physical entity than is the cell or, for that matter, the organism itself. . . . If I ask for a living chromosome, that is, for the only effective kind of chromosome, no one can give it to me except in its living surroundings any more than he can give me a living arm or leg. The doctrine of the relativity of functions is as true for the gene as it is for any of the organs of the body. They exist and function only in relation to other organs. Thus the last of the biological theories leaves us where the first started, in the presence of a power called life or psyche which is not only of its own kind but unique in each and all of its exhibitions."

That was 1931. In 1953, Watson and Crick drove a coach and horses through it, blew it out of the water. Genes are isolatable, they can be taken out of bodies, they can be sequenced, they can be put in bottles, they can be written out in a book and stored away in a library, and then at any time in the future they can be simply typed back into a machine and the original gene reconstituted. It could be put back into a living creature where it will work exactly the way it originally did. In the context of the gene, the understanding, the explanation is more or less total. And it was completely unexpected only a few decades ago.

My suspicion, my hunch, my hope, is that the same thing is going to be done for the conscious mind. Probably within the next century. Soul One will finally be killed, and good riddance. But in the process, Soul Two, far from being destroyed, will still be finding new worlds to conquer.

I'm going to end my prepared remarks by saying a little bit about Darwinism, because Darwinism is something which obviously Steve Pinker and I have in common in our approach to science. This, I think, may be the one place where possibly some slight disagreement may emerge. For me, Darwinism is not actually, surprisingly enough, the theory of the selfish gene. It's the theory of the selfish replicator. Darwinism is a much more general idea than the particular version of Darwinism which happens to explain life on this planet. Darwinism in this more general universal sense refers to the differential survival of any kind of self-replicating coded information which has some sort of power or influence over its probability of being replicated. DNA is the main kind of replicating entity that we know on this planet that has that property. When we look at living things on this planet, overwhelmingly the kind of explanation we should be seeking, if we ask what the functional significance is an explanation in terms of the good of the genes. Any adaptation is for the good of the genes which made that adaptation.