"Evidentialism" is the view about epistemic justification that identifies the extent to which a person is justified in believing a proposition with the extent to which the evidence the person has supports the truth of the proposition. Other doxastic attitudes such as withholding judgment and denying are also justified by the character of the person's evidence.

A full-scale evidentialist theory would explain what constitutes evidence, what it means to have a certain body of evidence, and what it means for a body of evidence to support a proposition to any given extent. Ordinarily, people count as evidence external things such as fingerprints and bank records. However, according to evidentialists, our fundamental evidence is constituted by our perceptual experiences, our apparent memories, and other mental states. A full-scale theory requires an account of what we have as this ultimate sort of evidence: It is unclear, for example, whether someone's...