ABSTRACT
An important warning: a common mistake is to overreact to Saul Kripke and H. Putnam, and to think that what has been shown is that all terms are natural kind terms or that all terms refer directly to their referents or are rigid designators. Kripke published his paper 'Identity and Necessity' in 1971, and the book that made him and his views famous, Naming and Necessity, in 1980. There are similarities between Putnam's account and John Locke's old discussion of real and nominal essence. A singular term such as, whose referent remains constant from world to world, is what Kripke calls a rigid designator. One might try to come up with some sort of grand unification theory, one that accounts for the cognitive dimension of language that exercised Gottlob Frege and Bertrand Russell but which accommodates the facts about reference and necessity that Kripke points out.
