Alfred Jules Ayer (1910-89) was a philosopher and a leading English representative of Logical Positivism. He was responsible for introducing the doctrines of the movement as developed in the 1920s and 1930s by the Vienna Circle group of philosophers and scientists into British philosophy. Ayer’s philosophy was also influenced by empiricism of David Hume and the logic of Bertrand Russell.
Although he was born and raised in London, Ayer’s father was a French Swiss national and his mother was a Dutch citizen of Jewish ancestry. He was educated as a scholarship student in classics at Eton and Christ Church, Oxford. At the age of 16, while at Eton, he also read the work of Bertrand Russell and was impressed by his essay Sceptical Essays and its argument that it is undesirable to believe a proposition when there is no ground for believing its truth. At Oxford, he was a student of Gilbert Ryle (1900-76) who described him as “the best student I have yet been taught by.” He also studied the works of the empiricist David Hume, A Treatise of Human Nature (1739) and Tractatus Logico-Philosophicus (1921) by Ludwig Wittgenstein. On Ryle’s suggestion, after graduating from Oxford in 1932, he went to study with Moritz Schlick in Vienna for a year. Schlick was the leader of the influential Vienna Circle of philosophers, scientists and other intellectuals.
At the age of 24, Ayer published a very influential first book, Language, Truth, and Logic (1936), which presented and built upon the logical positivist ideas of the Vienna Circle. It became one of the most widely read and successful philosophical books in the twentieth century.
Its central doctrine is based on the principle that if something cannot be verified as true through our own sensory experience of the external world, it is meaningless. According to this principle, there are two sorts of cognitively meaningful statements: those which are empirically verifiable and those which are analytic. Scientific statements and statements of ordinary fact belong to the first class, while statements of mathematic and of logic belong to the second. Ayer used this theory to argue that religious and metaphysical statements such as “God exists” are unverifiable and meaningless. Many of Oxford’s more traditional philosophers did not support such a view, making Ayer the “enfant terrible” of British philosophy.
Ayer’s second book, The Foundation of Empirical Knowledge (1940) focused on epistemology. His third important book, The Problem of Knowledge (1956), considered his finest work, has also been very influential in subsequent epistemological thinking in Britain and America. In this work, he discussed the problem of scepticism and tried to show how we could justifiably come to know truths about such phenomena as the external world, other minds, and the past.
After the Second World War, he became Grote Professor of the Philosophy of Mind and Logic at University College, London, in 1946. He became the Wykeham Professor of Logic at Oxford in 1959. In later years, Ayer turned to writing the history of philosophy, producing volumes on Voltaire, pragmatism, Wittgenstein, G. E. Moore, and Russell.
Ayer was also a public philosopher and played a prominent role in British intellectual and political life, supporting a variety of liberal causes. He campaigned against the British involvement in Vietnam War and served as the president of the Homosexual Law Reform Society (helping to change the public opinion on homosexual activity between consenting adults). He was also a successful broadcaster and made frequent appearances on the BBC.
Named as a fellow of the British Academy in 1952, a president of the Aristotelian Society from 1951 to 1952, a president of the British Humanist Association from 1966-1970, Alfred Jules Ayer was knighted in 1970. He died in 1989.