Define Private Language.

The concept of a "private language" is introduced by the philosopher Ludwig Wittgenstein in his later work, particularly in "Philosophical Investigations." Wittgenstein challenges the idea of an entirely subjective language that only one individual can understand. According to him, a private language is incoherent and impossible.

Wittgenstein argues that language derives its meaning through shared, public usage and communal practices. A private language, understood by an individual alone, lacks the necessary referential framework to establish meaning, as there is no external standard against which one's private symbols can be verified.

In the Philosophical Investigations, Wittgenstein presents the example of a person having a "beetle" in a box that only they can see. Since each person can only see their own private beetle, there is no way to ensure that the word "beetle" means the same thing for everyone, and thus the language lacks a communal foundation.

The notion of a private language challenges solipsism and reinforces Wittgenstein's later emphasis on the social and communal nature of language. For him, meaning is embedded in shared practices and public contexts, making the idea of a language that is entirely private and meaningful only to an individual untenable within his philosophical framework.