| The main goal of this dissertation is to defend the existence of a priori knowledge and justification. After elucidating the general notion of the a priori, in which I argue that a priori justification is experientially and nonexperientially defeasible and fallible, I present two arguments for the existence of the a priori: a parity argument with other epistemic sources and a new version of the Generality Argument. I then present a new forceful objection to the a priori---the Defeater Version of Benacerraf's Problem. I argue that in order to respond to this objection, we need to have some model of how a priori judgments could be reliable.;The rest of the dissertation is devoted to evaluating a variety of models and finally presenting my own. After critiquing divine illumination, natural selection, conventionalism, and Paul Boghossian and Christopher Peacocke's models, I present my own model, which I call the New Conceptual Role Theory. According to my theory, understanding a concept involves having implicit conceptions that approximately match the genuinely content-determining conceptions/uses for the concept, where the latter may be external to an individual. The content of a concept is determined to be that entity that makes all the principles mentioned in the genuinely content-determining conceptions true and the inferences mentioned valid. One's a priori judgments are reliably influenced by one's implicit conceptions, which are guaranteed, in virtue of understanding together with the above story, to be for the most part accurate. So, one's a priori judgments will be reliable, although fallible. I also argue that my model avoids Timothy Williamson's objections to the possibility of conceptual truth. So, this model demonstrates how a priori judgments can be reliable, and thus enables us to avoid the Defeater Version of Benacerraf's Problem. |
