I am quite wedded to the view that epistemologists should concern themselves with knowledge rather than our concept of knowledge. The analogy I like to draw here is with our understanding of (other) natural kinds.

No one would suggest that we can adequately investigate what makes something an acid, or what makes something aluminum, by bringing our pretheoretical intuitions about these things into reflective equilibrium by way of armchair theorising.

Bealer argues that the kind of naturalistic view which Quine holds will rob him of the ability to make the normative claims which (many) naturalists wish to make in epistemology. I don't think this is right about Quine, but I'm certain it's not right about my own view. To the extent that I can show that talk of knowledge is firmly rooted within empirical theories where it plays an important explanatory role, I thereby demonstrate its naturalistic credentials.

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.

Externalists reject any such view. I think that the idea that we can tell, simply by way of reflection, whether our beliefs are justified, is deeply commonsensical. More than that, the idea that responsible epistemic agents ought to reflect on their beliefs, and hold them only if they somehow pass muster, is utterly natural.

If one's interest is not in some global question about the possibility of knowledge, but about some particular mechanism or inferential tendency, this fact about our evolutionary origin is of no use at all in addressing questions about reliability.

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.