Abstract

Propositions are defined by abstraction from an equivalence relation on sentences. The equivalence is synonymy. The resulting view, Propositional Abstractionism, has roots in Frege’s work, and considerable advantages over competitors. The key to the advantages is that Propositional Abstractionism puts language first. Consequently, in metaphysics, granularity debates benefit from linguistic evidence; in logic, abstraction is a safeguard against higher-order paradoxes; in epistemology, questions of knowledge of propositions can be approached as questions about semantic competence. These benefits form a package that make Propositional Abstractionism a compelling hypothesis.