In the philosophy of language, the descriptivist theory of proper names (also descriptivist theory of reference) is the view that the meaning or semantic content of a proper name is identical to the descriptions associated with it by speakers, while their referents are determined to be the objects that satisfy these descriptions. Bertrand Russell and Gottlob Frege have both been associated with the descriptivist theory, which has been called the mediated reference theory or Frege–Russell view.

In the 1970s, this theory came under attack from causal theorists such as Saul Kripke, Hilary Putnam and others. However, it has seen something of a revival in recent years, especially under the form of what are called two-dimensional semantic theories. This latter trend is exemplified by the theories of David Chalmers, among others.

A simple descriptivist theory of names can be thought of as follows: for every proper name p, there is some collection of descriptions D associated with p that constitute the meaning of p. For example, the descriptivist may hold that the proper name Saul Kripke is synonymous with the collection of descriptions such as

The descriptivist takes the meaning of the name Saul Kripke to be that collection of descriptions and takes the referent of the name to be the thing that satisfies all or most of those descriptions.

A simple descriptivist theory may further hold that the meaning of a sentence S that contains p is given by the collection of sentences produced by replacing each instance of p in S with one of the descriptions in D. So, the sentence such as "Saul Kripke stands next to a table" has the same meaning as the following collection of sentences:

A version of descriptivism was formulated by Frege in reaction to problems with his original theory of meaning or reference (Bedeutung), which entailed that sentences with empty proper names cannot have a meaning. Yet a sentence containing the name 'Odysseus' is intelligible, and therefore has a sense, even though there is no individual object (its reference) to which the name corresponds. Also, the sense of different names is different, even when their reference is the same. Frege said that if an identity statement such as "Hesperus is the same planet as Phosphorus" is to be informative, the proper names flanking the identity sign must have a different meaning or sense. But clearly, if the statement is true, they must have the same reference. The sense is a 'mode of presentation', which serves to illuminate only a single aspect of the referent. Scholars disagree as to whether Frege intended such modes of presentation to be descriptions. See the article Sense and reference.

Russell's approach is somewhat different. First of all, Russell makes an important distinction between what he calls "ordinary" proper names and "logically" proper names. Logically proper names are indexicals such as this and that, which directly refer (in a Millian sense) to sense-data or other objects of immediate acquaintance. For Russell, ordinary proper names are abbreviated definite descriptions. Here definite description refers again to the type of formulation "The…" which was used above to describe Santa Claus as "the benevolent, bearded…." According to Russell, the name "Aristotle" is just a sort of shorthand for a definite description such as "The last great philosopher of ancient Greece" or "The teacher of Alexander the great" or some conjunction of two or more such descriptions. Now, according to Russell's theory of definite descriptions, such descriptions must, in turn, be reduced, to a certain very specific logical form of existential generalization as follows:

becomes