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.)

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.

The fact that we have been able to develop a successful science, which issues in ever more accurate predictions and broader explanations, is the real ground for confidence that we are in a position to gain knowledge of the world around us. At the same time, one might ask how it is that the cognitive equipment we have came about, and here, no doubt, our evolutionary origins are relevant.

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.

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.

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.

Ethologists thus have an interest in looking at these capacities for the reliable acquisition of belief, and it is not surprising that they have a name for the true beliefs which are the typical product of these reliable capacities. They call them items of knowledge. So I argue that talk of knowledge may thereby be seen to be embedded within a successful empirical theory.