Introduction

Abstract

For all I know I might be dreaming right now. Or perhaps there is an evil Demon deploying all his powers to deceive me. Maybe, even, I am a brain in a vat. On the other hand, maybe things are just the way they seem to me. Some philosophers are inclined to say that these considerations put me in an epistemological quandary; I just do not know whether any of my beliefs about the external world are true, indeed, whether there is an external world at all. Through these sorts of arguments, Descartes is reputed to have left to the modern student of philosophy a legacy. It is not, however, (just) the specter of skepticism that we have inherited (nor, of course, did we inherit Descartes’ substance dualism). Rather, it is the idea that, in the various scenarios sketched above, I might be having all the same thoughts, regardless of whether they are true or radically mistaken. This has been taken by some to suggest that my cognitive life is distinctively private and insulated from the rest of the world; the suggestion is that our cogitations are internal affairs, to be individuated independently of our environments.¹ We may call this Cartesian legacy internalism (or, for some purposes and in some contexts, individualism).