1940 – 2022
Saul Aaron Kripke (1940–2022) was an American philosopher and logician widely regarded as one of the most important figures in twentieth-century analytic philosophy. He revolutionized modal logic by developing possible-worlds semantics and made foundational contributions to philosophy of language through his theory of rigid designation and direct reference.
Developed Kripke semantics (possible-worlds semantics) for modal logic, providing the standard model-theoretic framework for necessity and possibility
Introduced the theory of rigid designators and direct reference in 'Naming and Necessity' (1980), overturning descriptivist theories of meaning
Distinguished the epistemic (a priori/a posteriori) and metaphysical (necessary/contingent) dimensions of propositions, showing they come apart
Offered an influential interpretation of Wittgenstein's rule-following paradox in 'Wittgenstein on Rules and Private Language' (1982)
Contributed to formal semantics for intuitionistic logic and the theory of truth (the Kripke fixed-point construction)