A direct reference theory, also called referentialism or referential realism, or referential fallacy, is a theory of language that claims that the meaning of a word or expression lies in what it points out in the world. The object denoted by a word is called its referent. Criticisms of this position are often associated with Ludwig Wittgenstein.
In the 19th century, mathematician and philosopher Gottlob Frege argued against it, and contrasted it with mediated reference theory. In 1953, with his Philosophical Investigations, Wittgenstein argued against referentialism, famously saying that "the meaning of a word is its use." Direct reference theory is a position typically associated with logical positivism and analytical philosophy. Logical positivist philosophers in particular have significantly devoted their efforts in countering positions of the like of Wittgenstein's, and they aim at creating a "perfectly descriptive language" purified from ambiguities and confusions.
The philosopher John Stuart Mill was one of the earliest modern advocates of a direct reference theory beginning in 1843. In his A System of Logic Mill introduced a distinction between what he called "connotation" and "denotation." Connotation is a relation between a name (singular or general) and one or more attributes. For example, ‘widow’ denotes widows and connotes the attributes of being female, and of having been married to someone now dead. If a name is connotative, it denotes what it denotes in virtue of object or objects having the attributes the name connotes. Connotation thus determines denotation. The same object can, on the other hand, be denoted with several names with different connotations. A name can have connotation but no denotation. Connotation of a name, if it has one, can be taken to be its meaning in Mill.
According to Mill, most individual concrete names are connotative, but some, namely proper names, are not. In other words, proper names do not have meaning. All general terms, on the other hand, are according to Mill connotative. In sum, Mill’s overall picture resembles very much the description theory of reference, though his take on proper names is an exception.