I was often asked how one could even make sense of this. Isn't the category of knowledge something that we project upon the world, rather than something that we discover in it?

When I got to college, I planned to be a math major, and, in addition to signing up for some math courses, I decided to take some philosophy. Quite by chance, I took a philosophy of science course in which the entire semester was devoted to reading Locke's Essay. I was hooked. For the next few semesters, I took nothing but philosophy and math courses, and it wasn't long before I realised that it was the philosophy that really moved me.

I do think that an understanding of contemporary work in the cognitive sciences has a profound effect on how one views the workings of the mind. It doesn't work the way we pretheoretically think it does. Such an understanding, of course, should have a large effect on one's views in philosophy of mind, but also in epistemology.

If we want to make sense of the possibility of successful inductive inference, and if we want to explain the possibility of laws of nature, we will need to appeal to something like natural kinds. This is, to be sure, a metaphysical commitment, but it is a metaphysical commitment that is implicit in science, as I see it.

Rather, although belief may be adequate for explaining the behavior of individual animals - an animal which believes that p will behave no differently from an animal which knows that p - talk of knowledge is necessary once one begins to look at explaining the cognitive capacities of a species.

In my view, philosophers have shown a great deal more respect for the first-person point of view than it deserves. There's a lot of empirical work on the various psychological mechanisms by way of which the first-person point of view is produced, and, when we understand this, I believe, we can stop romanticising and mythologising the first-person perspective.

Work on causal theories of knowledge - early work by Armstrong, and Dretske, and Goldman - seemed far more satisfying. As I started to see the ways in which work in the cognitive sciences could inform our understanding of central epistemological issues, my whole idea of what the philosophical enterprise is all about began to change. Quine certainly played a role here, as did Putnam's (pre-1975) work in philosophy of science, and the exciting developments that went on in that time in philosophy of mind.