Abstract

ABSTRACT: This paper develops an account of what it is for a proposition to be self- evident to someone, based on the idea that certain propositions are such that to fully understand them is to believe them. It argues that when a proposition p is self-evident to one, one has non-inferential a priori justification for believing that p and, a welcome feature, a justification that does not involve exercising any special sort of intuitive faculty; if, in addition, it is true that p and there exists no reason to believe that the proposition that p is incoherent, then one knows a priori that p. The paper argues that certain deeply contingent truths, e.g., the truth that I would now express by saying “I exist”, can be self-evident to, and thus known a priori by, the person they are about at the time they are about; but, since they cannot be known a priori, or even expressed, by anyone else or at any other time, they should not count as a priori truths.