Alfred Jules Ayer, the British philosopher, received his education at Eton, where he was a king's scholar, and at Christ Church, Oxford. After graduating in 1932, he spent some time at the University of Vienna familiarizing himself with the logical positivist movement, then little known among English-speaking philosophers. He returned to Oxford in 1933 as a lecturer in philosophy at Christ Church and in 1935 became a research fellow of the college. Army service in World War II kept him from philosophy until 1945, when he went back to university teaching as fellow and dean of Wadham College, Oxford. In the following year he became Grote professor of the philosophy of mind and logic at University College, London, where he remained until his return to Oxford as Wykeham professor of logic in 1959.

Ayer's first book, Language, Truth and Logic, was published in 1936. Its combination of lucidity...