Abstract

This dissertation is a systematic study of Wittgenstein's ideas on non-significant propositions, specifically tautologies, mathematical propositions, scientific laws in the Tractatus, grammatical propositions in the Investigations, and Moore-type propositions in On Certainty . My aim is to show that these propositions are closely connected. I take Wittgenstein's discussions of them to be a theme developed both in the early and later periods of his philosophy. His idea is that since such propositions cannot be properly regarded as empirical or true or false, they are radically different from propositions that are. He sees the conflation of these two kinds of proposition as a major source of philosophical illusions. For this reason, it is important for him to clarify the logical status of such nonsignificant propositions