Revisability, Reliabilism, and A Priori Knowledge

Proponents of a priori knowledge face two formidable tasks: (i) providing an illuminating characterization of the concept of a priori knowledge; and (z) providing cogent reasons for believing that some of our knowledge is indeed a priori. There have been two general approaches to defending the existence of a priori knowledge. Some begin by providing a general characterization of such knowledge and then show that there are plausible examples of knowledge which satisfy the conditions in the characterization.' On this approach, the defense of the existence of such knowledge depends on the analysis of the concept of a priori knowledge. The second approach treats these issues independently. In particular, it is argued that certain classes of statements, such as mathematical statements or necessary statements, cannot be known on the basis of experience and, hence, are known a priori without any attempt to offer a general characterization of a priori knowledge.' Recent critics of the a priori fall into two similar camps. Some attempt to argue against the existence of a priori knowledge without presupposing any particular analysis of the concept. Paul Benacerraf, for example, adopts this approach by raising doubts about the existence of the cognitive faculty of intuition which is often invoked by proponents of the a priori as the source of such knowledge.3 The second prominent line of