Private language argument

The private language argument argues that a language understandable by only a single individual is incoherent, and was introduced by Ludwig Wittgenstein in his later work, especially in the Philosophical Investigations. The argument was central to philosophical discussion in the second half of the 20th century. In the Investigations, Wittgenstein does not present his arguments in a succinct and linear fashion; instead, he describes particular uses of language, and prompts the reader to contemplate the implications of those uses. As a result, there is considerable dispute about both the nature of the argument and its implications. Indeed, it has become common to talk of private language arguments. Historians of philosophy see precursors of the private language argument in a variety of sources, notably in the work of Gottlob Frege and John Locke. Locke is also a prominent exponent of the view targeted by the argument, since he proposed in his An Essay Concerning Human Understanding that the referent of a word is the idea it stands for. The private language argument is of central importance to debates about the nature of language. One compelling theory about language is that language maps words to ideas, concepts or representations in each person's mind. On this account, the concepts in one's head are distinct from the concepts in another's head. One can match their concepts to a word in a common language, and then speak the word to another. The listener can then match the word to a concept in their mind. So the shared concepts, in effect, form a private language which one can translate into a common language and so share. This account is found for example in An Essay Concerning Human Understanding, and more recently in Jerry Fodor's language of thought theory. Wittgenstein argues, in his later work, that this account of private language is inconsistent. If the idea of a private language is inconsistent, then a logical conclusion would be that all language serves a social function.