In Naming and Necessity, Saul Kripke fundamentally challenges the long-dominant descriptivist theory of names, a view advanced by Gottlob Frege and Bertrand Russell that holds that a proper name is synonymous with a definite description or a cluster of descriptions. Kripke argues against this by introducing the concept of “rigid designators” that refer to the same object in every possible world. He posits that proper names function as rigid designators and that this model better explains how language works, especially in contexts involving counterfactuals and modal statements. By demonstrating that a name’s connection to its referent is more direct and stable than any associated description, Kripke dismantles the descriptivist framework and asserts a causal-historical chain of reference.

The core of Kripke’s argument lies in the intuitive way we evaluate statements about counterfactual situations. He uses the example “Aristotle was fond of dogs” (6). According to the rigidity thesis, this statement is true of a counterfactual world if and only if the specific man, Aristotle, would have been fond of dogs in that world. A descriptivist theory, by contrast, might analyze “Aristotle” as synonymous with a description like “the last great philosopher of antiquity” (6). In a possible world where Plato had a different, more brilliant student who overshadowed Aristotle, that other person would be the last great philosopher. The descriptivist analysis would then incorrectly make that other person’s fondness for dogs the relevant issue for the truth of the statement about Aristotle. This thought experiment reveals that the name “Aristotle” sticks to one individual across all possible scenarios, whereas the referent of the description can change. This stability is the hallmark of a rigid designator, and it reflects a fundamental aspect of how proper names are used.

Kripke further shows that descriptivism struggles to account for modal statements, such as “It might have been the case that Aristotle was not a philosopher” (13). On a descriptivist account, this statement might translate to the seemingly contradictory claim, “It might have been the case that the greatest philosopher of antiquity was not a philosopher” (13). By identifying “Aristotle” as a rigid designator, the statement instead considers a possible world where that particular man, Aristotle, chose a different path in life. Our ability to speak meaningfully about what historical figures might have done demonstrates that their names refer to them independently of the achievements we associate with them. The properties commonly used to identify a person are often contingent, not essential, and a theory of reference must be able to accommodate this fact.

Finally, Kripke rejects attempts to save descriptivism by arguing that the phenomena he describes can be explained by scope distinctions by treating names as nonrigid designators that are always given wide scope over modal operators. Kripke points out that the issue of rigidity applies even to simple, non-modal sentences where no scope distinctions are possible. The central question concerns a sentence’s truth conditions with respect to counterfactual situations, a matter that exists independently of whether modal operators appear in the sentence. He asserts that “we have a direct intuition of the rigidity of names” (14), which cannot be reduced to a linguistic convention about scope.