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.

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.

The great philosophers of the 17th and 18th centuries did not think that epistemological questions floated free of questions about how the mind works. Those philosophers took a stand on all sorts of questions which nowadays we would classify as questions of psychology, and their views about psychological questions shaped their views about epistemology, as well they should have.

When I think about discussions at the Society for Philosophy and Psychology, a group which includes not only philosophers and psychologists, but also computer scientists and linguists, it is noteworthy that one can't always tell just from the content of particular contributions from the audience, whether a given questioner is a philosopher or an empirical scientist.

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.

Bealer has a number of reasons for thinking that a naturalistic epistemology is self-undermining. Let me focus on one of these. (I've tried to take on all of them in the first chapter of Knowledge and Its Place in Nature.)

The idea that we should check on our unreflective belief acquisition sounds great, but we need to know whether the processes of reflection which we put to work serves to improve our reliability or not.