Abstract

Recent scholarship suggests that Descartes’s effort to establish a truth criterion is not viciously circular (notwithstanding its reputation)---a fact that invites closer scrutiny of his epistemological program. One of the least well understood features of the project is his deduction of a truth criterion from theistic premises, a demonstration Descartes says he provides in the Fourth Meditation: the alleged proof is not revealed by a casual reading, nor have commentators fared any better; in general, the relevance of the Fourth Meditation has not been duly appreciated. This paper reconstructs the argument of the Fourth Meditation, detailing the steps in the demonstration of the criterion and clarifying its role in the larger program. Surprisingly, Descartes deduces a truth criterion more fundamental than clarity and distinctness; this more fundamental criterion helps explain what are otherwise cryptic (though central) epistemological moves in the Sixth Meditation.