Lunacy and Scepticism: Notes on the Logic of Doubt Concerning the Existence of an External World

Abstract

AbstractThis article develops a logical (or semantic) response to scepticism about the existence of an external world. Specifically, it is argued that any doubt about the existence of an external world can be proved to be false, but whatever appears to be doubt about the existence of an external world that cannot be proved to be false is nonsense, insofar as it must rely on the assertion of something that is logically impossible. The article further suggests that both G. E. Moore and Ludwig Wittgenstein worked towards the same solution but left their work unfinished.