The economist, John Maynard Keynes, when criticised for shifting his position on monetary policy, retorted: "When the facts change, I change my mind. What do you do, sir?" Point taken. Yet, despite the way the Edge 2008 Question has been framed, in science it is not always true that it requires new facts to change people's minds. Instead, as Thomas Kuhn recognised, at major turning points in the history of science, theorists who have previously found themselves struggling to make sense of "known facts", sometimes undergo a radical change in perspective, such that they see these same facts in a quite different light. Where people earlier saw the rabbit, they now see the duck.
In my own research on consciousness, I have changed my mind more than once. I expect it will happen again. But it has not — at least so far — been because I learned any new facts. Contrary to the hopes of neuroscientists on one side, quantum physicists on the other, I'm pretty sure all the facts that we need to solve the hard problem are already familiar to us — if only we could see them for what they are. No magic bullet is going to emerge from the lab, from brain imaging or particle accelerators. Instead, what we are waiting for is merely (!) a revolutionary new way of thinking about things that we all, as conscious creatures, already know — perhaps a way of making those same facts unfamiliar.
What is the hard problem? The problem is to explain the mysterious out-of-this-world qualities of conscious experience — the felt redness of red, the felt sharpness of pain. I once believed that the answer lay in introspection: "thoughts about thoughts", I reckoned, could yield the requisite magical properties as an emergent property. But I later realised on logical (not factual) grounds that this idea was empty. Magic doesn't simply emerge, it has to be constructed. So, since then, I've been working on a constructivist theory of consciousness. And my most promising line yet (as I see it) has been to turn the problem round and to imagine that the hardness of the problem may actually be the key to its solution.
Just suppose that the "Cartesian theatre of consciousness", about which modern philosophers are generally so sceptical, is in fact a biological reality. Suppose indeed , that Nature has designed our brains to contain a mental theatre, designed for the very purpose of staging the qualia-rich spectacle on which we set such store. Suppose, in short, that consciousness exists primarily for our entertainment and amazement.
I may tell you that, with this changed mind-set, I already see the facts quite differently. I hope it does the same for you, sir.