Abstract

Wittgenstein takes Moore to task for confusing knowledge with the non‐epistemic brand of conviction that logically underlies it, and he drives a categorial wedge between them: 'knowledge and certainty belong to different categories'. However basic knowledge is understood, it must be capable of standing in logical relations to whatever judgements rest on it. For example, it must be capable of being consistent or inconsistent with them. But this means that even basic knowledge must involve propositional content. In certain circumstances a man cannot make a mistake. If Moore were to pronounce the opposite of those propositions which he declares certain, we should not just not share his opinion: we should regard him as demented. In thus logically closing the door to doubt and mistake as regards our basic certainties, Wittgenstein closes the door to universal skepticism, and thereby also to the contextualism Michael Williams attributes to Wittgenstein.