A. J. Ayer 1910 – 1989

Alfred Jules Ayer was a British philosopher and the most prominent representative of logical positivism in the English-speaking world. Having spent time with the Vienna Circle while still in his early twenties, he returned to Oxford and published Language, Truth and Logic at twenty-six, an uncompromising defense of the verification principle and an emotivist analysis of ethics that became one of the most widely read philosophy books of the century. He held chairs at London and Oxford, and his views, while progressively moderated, continued to define the agenda of mid-century analytic philosophy.

Alfred Jules Ayer was born in 1910 in St John's Wood, London, to a Swiss-French Calvinist father and a Dutch-Jewish mother whose family had founded the Citroen automobile company. After Eton and a first in Greats at Christ Church, Oxford, he spent the winter of 1932-1933 in Vienna at the urging of his tutor Gilbert Ryle, attending the meetings of the Vienna Circle and bringing back the doctrines of logical positivism in their most uncompromising form.

His Language, Truth and Logic, written before his twenty-fifth birthday and published in 1936, is the best-known statement of logical positivism in English: only tautologies and empirically verifiable propositions express genuine cognitive content; metaphysics, theology, and ethics, in their traditional forms, are eliminated as nonsense or reduced to expressions of attitude. After war service in intelligence he succeeded Stuart Hampshire at University College London in 1946 and from 1959 held the Wykeham Chair of Logic at Oxford. His later books include The Foundations of Empirical Knowledge (1940), The Problem of Knowledge (1956), and the philosophical biographies of Russell and Hume.

Ayer's later philosophy moderated the early positivism — the second edition of Language, Truth and Logic concedes as much — but he remained the most prominent British philosophical advocate of empiricism, atheism, and a secular humanist public stance. Knighted in 1970, he died in London in June 1989, after the unusual interlude of a near-death experience that he reported with characteristic candor in print.