LUDWIG WITTGENSTEIN, Austrian-born philosopher (d. 1951); an Austrian philosopher who worked primarily in the foundations of logic, the philosophy of mathematics, the philosophy of mind and the philosophy of language. His influence has been wide-ranging and he is generally regarded as one of the 20th century’s most important philosophers.

Before his death at the age of 62, the only book-length work Wittgenstein had published was the Tractatus Logico–Philisophicus,[“Philosophical Investigations”], which Wittgenstein worked on in his later years, was published shortly after he died. Both of these works are regarded as highly influential in analytic philosophy.

Ludwig Wittgenstein seems to have been uncomfortable with his sexuality. Certainly, he was very secretive about his sexual interests and activities. His secretiveness is not altogether surprising, considering the fact that homosexuality was illegal in Austria and Britain during his lifetime. Therefore, details of his emotional and sexual life are sparse.

William W. Bartley first broached the subject of Wittgenstein’s homosexuality in his 1973 biography and received considerable censure and disapproval from the philosophy establishment. Apparently, in his student days in Vienna, Wittgenstein occasionally cruised the Prater, a large public park, where he met rough trade youths; he seems to have continued this activity later in England. However, Wittgenstein is also believed to have had long-term affairs with men of his own class, such as the philosopher Frank Ramsey and the architect Francis Skinner.