During the past decade a new twist in the debate regarding the a priori has unfolded. A number of prominent epistemologists have challenged the coherence or importance of the a priori—a posteriori distinction or, alternatively, of the concept of a priori knowledge. My focus in this paper is on these new challenges to the a priori. My goals are to (1) provide a framework for organizing the challenges, (2) articulate and assess a range of the challenges, and (3) present two challenges of my own.