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Thinker · 1940 CE–2022 CE

Saul Kripke

Kripke's "Naming and Necessity" (delivered as lectures at Princeton in 1970, published 1980) overturned the dominant Frege-Russell descriptivist account of proper names, arguing instead that names are rigid designators whose reference is fixed by an initial act of "baptism" and transmitted through a causal-historical chain of use rather than by a cluster of identifying descriptions. Combining this with the possible-worlds semantics for modal logic he had developed as a teenager, he distinguished the metaphysical modal status of a statement (necessary or contingent) from its epistemic status (a priori or a posteriori), arguing that some truths, such as identity statements between rigid designators (e.g., "water is H2O"), are necessary yet knowable only a posteriori, while others (e.g., statements fixing a standard of measurement) are contingent yet knowable a priori.

Intellectual setting

Kripke delivered the lectures that became "Naming and Necessity" at Princeton in 1970, into a philosophical environment shaped by descriptivist theories of reference from Frege and Russell and by the later Wittgenstein's skepticism about naming; his own possible-worlds ("Kripke") semantics for modal logic, developed while still a teenager in the late 1950s, had already reshaped how philosophers formalized necessity and possibility. He held professorships at Rockefeller University, then Princeton University, and finally the CUNY Graduate Center, where he founded the Saul Kripke Center.

Key ideas

Rigid designators and the causal theory of reference

Kripke argued that proper names are rigid designators - referring to the same individual in every possible world in which that individual exists - and that their reference is fixed not by a cluster of descriptions the speaker associates with the name but by an original "baptism" whose use is then transmitted through a causal-historical chain of speakers.

The necessary a posteriori and the contingent a priori

Against the assumption that necessity and apriority coincide, Kripke argued that identity statements linking two rigid designators (such as "Hesperus is Phosphorus" or theoretical identities like "water is H2O") are metaphysically necessary but knowable only through empirical investigation, while some stipulative truths are contingent yet knowable a priori.

Legacy

Naming and Necessity is widely regarded as one of the most influential works of twentieth-century analytic philosophy, reviving metaphysical essentialism and a broadly causal, anti-descriptivist theory of reference that reshaped philosophy of language, metaphysics (especially debates over identity and essence), and philosophy of mind, where his rigid-designator argument became a central objection to type-identity theories of the mental. His possible-worlds semantics remains the standard framework for modal and intensional logics, and "Wittgenstein on Rules and Private Language" (1982) opened the ongoing debate over the "Kripkenstein" skeptical paradox about meaning.