I think that when I first suggested the idea that knowledge should be viewed as a natural kind, many people thought this was just crazy.

No one worries terribly much about who the questions belong to, or whether a given contribution is really philosophy or, instead, properly nothing but science. Perhaps another way to put this is that, although I think that knowledge is a natural kind, I don't think that philosophy is.

I largely defer to the cognitive ethologists. I believe that the arguments that they make on this score are extremely persuasive. More than this, I do think as well that a priori objections by philosophers to successful research programs in the sciences have a very bad track record.

Here, there is simply no substitute for the kind of work that experimental psychologists do, work which shows some mechanisms to be quite reliable, and others to be quite unreliable.

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.

The fact that these scientific theories have a fine track record of successful prediction and explanation speaks for itself. (Which is not to say that I don't directly discuss the work of those philosophers who would disagree.) But even if we grant this, many will argue that scientific knowledge in humans, and, indeed, reflective knowledge in general, is quite different in kind from the knowledge we see in other animals.

I do agree with Stich that a quick move from our evolutionary origins to the reliability of our cognitive mechanisms is not legitimate. As I see it, the case for the reliability or unreliability of various cognitive mechanisms lies elsewhere.