American logician and philosopher. Born in New York and educated at Harvard and Oxford, Kripke made his early reputation as a logical prodigy, especially through work on the completeness of systems of modal logic. The three classic papers are ‘A Completeness Theorem in Modal Logic’ (1959, Journal of Symbolic Logic), ‘Semantical Analysis of Modal Logic’ (1963, Zeitschrift für Mathematische Logik und Grundlagen der Mathematik) and ‘Semantical Considerations on Modal Logic’ (1963, Acta Philosophica Fennica). In Naming and Necessity (1980), Kripke gave the classic modern treatment of the topic of reference, both clarifying the distinction between names and definite descriptions, and opening the door to many subsequent attempts to understand the notion of reference in terms of a causal link between the use of a term and an original episode of attaching a name to a subject. His Wittgenstein on Rules and Private Language (1983) also proved seminal, putting the rule-following considerations at the centre of Wittgenstein studies, and arguing that the private language argument is an application of them. Kripke has also written influential work on the theory of truth and the solution of the semantic paradoxes.