While my discussion must be brief, I hope to suggest (i) that on an externalist conception of justification, a person could never justifiably believe that she actually is justified in believing naturalism to be true; (ii) that an externalist conception of justification is "unnatural," either being itself an a priori concept, or presupposing a priori concepts; and (iii) that, as an implication of (i) and (ii), an (at least partially) internalist conception of justification is necessary to make a case for a justified belief in naturalism--assuming that such a case can otherwise be made.
The conditional "If a belief's etiology is reliable, then the belief is justified" is an a priori claim that in no way seems analytically true.
The fourth chapter argues we must consider the perceptual givenness of the a priori. A Kantian objection, however, states that perception is already intellectualized and the condition for this intellectualization cannot be found in perception itself.
Part 2 examines this subjective a priori. Chapter 6 argues the subject 'has the capacity for comprehending the a priori proffered to him and, once given, recognized by him' (121-2).
The appeal to (allegedly) a priori knowledge is central to Cassam's accounts of the possibility of perceptual knowledge and of knowledge of other minds.
On Cassam's account, 'a priori knowledge is knowledge that has its source' in a 'non-experiential ...