Abstract

There is an epistemological skepticism that I might be dreaming now, or I might be a brain in a vat (BIV). There is also a demonstration that derives the skeptical conclusion about knowledge of the external world from the premise C1, i.e., I do not know “I am not dreaming (not a BIV) now.” Pessimistic critics (e.g., F. Strawson, B. Stroud) consider that the refutation of C1 is impossible, whereas others have attempted the direct refutation of C1 (e.g., G. E. Moore, H. Putnam, C. Wright), and some (e.g., F. Dretske, R. Nozick) have attempted to refute the closure principle of knowledge used in the demonstration while permitting the validity of C1. Another scholar, M. Williams, maintains that the skeptical demonstration is true only if we presuppose the epistemological premise that we choose to accept or reject at will. It seems that most critics tend to adopt a strategy that allows them to effectively avoid the skeptical consequence, thereby conceding the validity of C1. However, it is difficult to say whether their attempts succeeded, and in my opinion, they are indeed unsuccessful. This is because their concession to Descartes’ argument is insufficient. Their lack of success could also stem from the incompletion of Descartes’ own methodological doubt. The somewhat paradoxical‐sounding aim of this thesis is to show that the skeptical paradox about knowledge can be dissolved only if the Cartesian skepticism is extended far beyond the endpoint of his attempt. The argument of this thesis is based on the important arguments of Wittgenstein's On Certainty （OC）