How Not to Reject the a Priori*

Abstract

According to one influential argument against the existence of a priori knowledge, there is no a priori knowledge because (i) no belief is immune to revision, and (ii) if there were a priori knowledge, at least some beliefs would be unrevisable. A version of this argument was famously advocated by W. V. Quine, and is still popular among many naturalist philosophers. The aim of this paper is to examine and reject this argument against the a priori. The paper starts by discussing the thesis (i) and its role in Quine’s Web of Belief model. It is suggested that this thesis faces some important challenges that might jeopardize its use in the above argument against the a priori. Premise (ii) of the argument is then discussed. Philip Kitcher has famously defended a version of premise (ii). His arguments are assessed and rejected. The conclusion is that we have no good reason to accept (ii), and, with it, this argument against the a priori. The paper ends by proposing an account of the a priori that is perfectly compatible with (i).