Abstract

David K. Lewis was a central player in the golden age of linguistics‐philosophy interaction, and he and his work were important parts of what made that age golden. This chapter discusses some of Lewis's ideas that have been most important for linguists, especially but not only for formal semanticists, and some of the influence his ideas have had. It provides Lewis's distinction between a language as an abstract object and the use of a language by a community, and its importance for defending the non‐psychologistic foundations of formal semantics. The chapter discusses some issues of importance to linguists connected with Lewis's work on possible worlds, modal realism, conditionals, and counterpart theory in brief. It highlights a number of specific ideas that have influenced linguists. The chapter presents David's important role in helping linguists and philosophers understand each other and cooperate in working on the syntax and semantics of natural languages.