17th century philosophers were not in a position to understand the mind as well as we can today, since the advent of experimental methods in psychology. It shows no disrespect for the brilliance of Descartes or Kant to acknowledge that the psychology which they worked with was primitive by comparison with what is available today in the cognitive sciences, any more than it shows disrespect for the brilliance of Aristotle to acknowledge that the physics he worked with does not compare with that of Newton or Einstein.

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.

What I hankered for was an account of knowledge which would do far more than get our intuitions about cases right; I wanted a kind of account which would somehow be explanatory.

There is a worry that many have expressed that, on the naturalistic way of approaching philosophical questions, philosophy will somehow be co-opted by science. I'm not much worried about this.

Internalist approaches to epistemology, I believe, have a great deal of intuitive appeal. Internalists believe that the features in virtue of which a belief is justified must somehow be internal to the agent. On some views, this amounts to the claim that these features must be accessible to introspection and armchair reflection. On others, it amounts only to the claim that they must be mental features.

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.

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.)