Abstract
In this paper I argue that an adequate and coherent account of Descartes’ concepts of mental representation, ideas, clarity and distinctness, obscurity and confusion, and material falsity requires that one takes Descartes seriously whenever he makes a distinction between what an idea appears to represent and what it actually represents, and that one understands an idea’s representing a thing in terms of the objective existence in the mind of the essence of that thing. The paper also contains a logical articulation of most of these views, in a manner which shows overall coherence