Abstract

This dissertation explores the relationship between an extensive skepticism concerning the existence of the world and the concept of mental representation in Sextus Empiricus and Descartes. In Chapter 1, it is argued, against the traditional interpretation, that Sextus does espouse such an extensive skepticism; that, at the same time, he is using a very strong causal concept of experience according to which the object of the experience is 'the cause' of the experience; and that he can consistently embrace these two positions because his skepticism is flexible enough that he can always turn around and undermine the very presuppositions implicit in the use of a concept, which he has previously used to prove a skeptical point. Chapter 1 also includes an examination of Descartes's skepticism in the First Mediation, and it is argued that this skepticism undermines not only the Scholastico-Aristotelian causal view of mental representation, but also the weaker principle to the effect that we cannot have representations of simple things that compose those complex representations are caused by similar simple things. But Descartes's skepticism in the First Meditation is not as flexible as Sextus's. Hence, he cannot overturn his skeptical arguments by using any strong causal principle of mental representations. Chapters 2 and 3 together include an extensive defense of the view that the causal principle that Descartes uses in the Meditations to prove the existence of God and of physical objects is so weak as to allow that all our ideas--except the idea of God--are generated by our minds, and that this is the only principle he uses and needs in the Meditations and elsewhere. To this end, Chapter 2 examines the concepts of objective reality, material falsity, etc. It includes a defense of an interpretation of Descartes's view of ideas, according to which ideas have two levels of content: a seemingly representational and a truly representational. I relate this interpretation to his views on objective reality, material falsity, sensible qualities, the causes of innate ideas, and the nature of sensory perception and imagination