Photography by Michael Sugrue

It's an unseasonably warm spring day on campus and you've got a hankering for an ice cream cone. Will you pick chocolate or something more exotic? Standing indecisively, you look up to see a crazy little dog named Russell catching a ball in midair. Russell's well known around Berkeley. He's a robot and he fetches like nobody's business. You marvel at his abilities and then go for chocolate. Which is more likely: that you possess free will and used it to make your ice cream choice? Or that a dog like Russell could exist? Philosopher John Searle has thought a lot about the nature of consciousness and the prospects for the kind of artificial intelligence that would produce a conscious robot. For Searle, questions about human consciousness and thinking machines are intimately intertwined. Author of 17 books, including his most recent, Freedom and Neurobiology: Reflections on Free Will, Language, and Political Power, Searle is the Willis S. and Marion Slusser Professor of Philosophy. He has been at UC Berkeley since 1959. Although he grapples daily with questions such as "What is the nature of causation?" and "How do brains cause minds?" he can discuss his process as though he's talking to his neighbor across the back fence. I met Searle in his office, where a poster of his downhill-ski racing days while at Oxford hangs above a bulging bookshelf.

Q: In Freedom and Neurobiology as well as some of your other work, you borrow from the natural sciences to further your philosophical inquiries. Why?

Searle: I don't make a sharp distinction between philosophy and other disciplines, and so when I am working on a problem I am very opportunistic. My general strategy is to use any weapon that works when tackling a philosophical problem. There are many puzzling philosophical questions that have related issues in neurobiology. So I learn what neurobiology I can. Some philosophical problems have scientific solutions, but many do not. For example, questions about the good society and leading an ethical life are beyond the scope of the natural sciences.

I think some of the problems of consciousness will have neurobiological solutions. We don't know the solutions yet, but we have made progress on several questions: How do neurobiological processes in the brain cause conscious experiences? How are those conscious experiences realized in the brain—that is, where are they exactly in the brain?

One of the tasks of philosophical analysis is to get these questions into a good enough shape so that they can be solved using scientific methods. To some extent that has already happened. But it took a long time because many neurobiologists had made a philosophical mistake. They thought that consciousness was not a scientific problem at all, but rather the domain of philosophers and theologians.

An even worse mistake was the theory that consciousness is just a computer program, which has nothing to do with neurobiology.