The themes of Austrian philosopher's Ludwig Wittgenstein's Philosophical Investigations (1953) include the nature of philosophy itself, language, and what Wittgenstein calls "language games." Wittgenstein spent a long time writing this book, which was published after his death in 1951. Wittgenstein was not a typical philosopher in many ways. He rejected the environment of the university, which he found insufficient for practicing philosophy, he served in World War I, and he was a schoolteacher (where he was subject to some controversy after hitting his students). Despite this, Wittgenstein's mentor Bertrand Russell called Wittgenstein a genius.

In Philosophical Investigations, Wittgenstein rejects philosophy as a discipline that searches for theory. Rather, Wittgenstein claims that philosophy should teach us how to reconcile our misunderstandings of the universe. Wittgenstein further proposes that ambiguities surrounding languages are the root of all philosophical problems. Therefore, he sets himself to identifying the nature of language.

Wittgenstein adduces St. Augustine's description of language. Augustine explains that he learned language by seeing his elders point to things and say the name of the object emphatically. Wittgenstein seeks to dismantle this view and so imagines a primitive version of this language wherein builders know only the names of words such as "hammer," "block," "pillar" and "slab." Even if we add demonstrate words such as "this" and "that" as well as colors to describe these objects, ultimately, Wittgenstein maintains that this sort of language can not expand adequately. Thus, this Augustinian view of language it is an unsatisfactory one.

Accordingly to Wittgenstein, the meaningfulness of language is derived from the specific use of words, and it is misguided to try to come up with an overall guiding framework for understanding language (e.g. as a signifier and signified). Wittgenstein uses several examples of "language games" to demonstrate the variety of ways in which language can be used (even the word "game" itself, for example does not have a strict definition). The concept of language games signifies both the fact that language is an activity and the diversity of this activity.