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.

So I do, of course, reject much that is central not only to the psychology of Descartes and Kant, but to their epistemology as well. No doubt, the best available theories of today will look primitive in comparison with what we are in a position to understand hundreds of years from now.

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.

For one thing, I think that there are questions which philosophers raise which, although science bears on them, are not typically the central focus of those who work in the sciences. At the same time, I don't have a view of philosophy which marks it out as different in kind from scientific work

The worry that unreflective belief acquisition may be unreliable, after all, applies equally to reflective belief acquisition: it too may be unreliable. To my mind, the plausibility of internalist views about justification is dramatically decreased when one becomes vividly aware of what introspection and reflection actually achieve.

I have made some headway in addressing these questions, however, and succeeded in explaining how it is that the category of knowledge might play an important role in empirical theories. To the extent that talk of knowledge can be shown to play an explanatory role in such theories, the analogy I wish to make with paradigm natural kinds such as acids and aluminum starts to make a good deal of sense. This is, of course, connected with the issue of the role of intuitions in philosophy.

I believe, that empirically informed approaches to the question have issued in more illuminating answers than the old armchair approaches. But I think that it would be a terrible mistake to give up on addressing normative questions in epistemology.