Abstract

Perhaps the most pervasive conviction within the Western epistemological tradition is that in order for a belief to constitute knowledge it is necessary (though not sufficient) that it be epistemically justified: that the person in question have a reason or warrant which makes it at least highly likely that the belief is true. Historically, most epistemologists have distinguished two main sources from which such justification might arise. It has seemed obvious to all but a very few that many beliefs are justified by appeal to one’s experience of the world. But it has seemed equally obvious to most that there are other beliefs, including many of the most important ones that we have, which are justified in a way which is entirely independent of any appeal to such experience, justified, as it is usually put, a priori, by reason or pure thought alone.