In this article I present a summary of Bertrand Russell's protracted attempts to solve the problem of the unity of the proposition, and explain the significance of the problem for Russell's philosophy. Unlike many other accounts which take the problem to be confined to Russell's early theories of propositional content, I argue that the problem (or variants of it) is a recurring theme throughout the whole of Russell's career.

This chapter contains section titled: Stage‐setting Frege and Russell: simple abbreviation theories Cluster theories of proper names Some general principles Some critical consequences The significance of proper names Proper names and meaning.