Few concepts have been considered as essential to the theory of knowledge and rational belief as that of evidence. The simplest theory which accounts for this is evidentialism, the view that epistemic justification for belief—the kind of justification typically taken to be required for knowledge—is determined solely by considerations pertaining to one's evidence. In this ground-breaking book, leading epistemologists from across the spectrum challenge and refine evidentialism, sometimes suggesting that it needs to be expanded in quite surprising directions. Following this, the twin pillars of contemporary evidentialism—Earl Conee and Richard Feldman—respond to each essay. This engaging debate covers a vast number of issues, and will illuminate and inform.