Abstract

This dissertation addresses the question whether externalist theories of thought content provide a satisfactory response to the traditional problem of skepticism about the external world. I address two questions. If externalist theories of thought content are true, do they provide a satisfactory response to skepticism about the external world? Are externalist theories of thought content true? My answer to the first question is yes, and to the second no. The argument of the dissertation is divided into three parts. In the first part, I argue that skepticism about the external world rests on two fundamental assumptions about the mind-world relation. The contents of the mind are logically independent of the nature of the world around us. The contents of the mind are all the evidence we have for the nature of the world around us. Externalism attacks the first of these assumptions. In the second part, I criticize crucial and representative arguments for externalism by Hilary Putnam, Tyler Burge, and Donald Davidson. In the third part, I argue directly that the thesis of externalism is incorrect. The arguments in this part divide into three groups. The first shows that we cannot retrieve from our causal relations with our environment a determinate picture of the contents of our thoughts, without assuming that what determines those thoughts is not logically dependent on the environment. The second shows that if externalism were true, thought content would not be causally relevant to what we do. The third argues that attention to the first person point of view shows that thought content cannot plausibly be thought to be determined by external relations