Many philosophers take the distinguishing mark of their subject to be its a priori status. In their view, where empirical science is based on the data of experience, philosophy is founded on a priori intuitions. In this paper I shall argue that there is no good sense in which philosophical knowledge is informed by a priori intuitions. Philosophical results have just the same a posteriori status as scientific theories. My strategy will be to pose a familiar dilemma for the friends of a priori philosophical intuitions. I shall ask them whether their intuitions are supposed to be analytic or synthetic. And then I shall argue that, if the intuitions are analytic, they may be a priori, but will be philosophically uninteresting; while, if they ar...