Ayer was president of the Homosexual Law Reform Society for a time; he remarked, "as a notorious heterosexual I could never be accused of feathering my own nest."

Though primarily interested in his intellectual pursuits, he was very keen on sports, particularly rugby, and reputedly played the Eton Wall Game very well.

After graduating from Oxford, Ayer spent a year in Vienna, returned to England and published his first book, Language, Truth and Logic, in 1936.

This first exposition in English of logical positivism as newly developed by the Vienna Circle, made Ayer at age 26 the enfant terrible of British philosophy.

[10] In the Second World War, Ayer served as an officer in the Welsh Guards, chiefly in intelligence (Special Operations Executive (SOE) and MI6[11]).

He was also obsessed with sport: he had played rugby for Eton, and was a noted cricketer and a keen supporter of Tottenham Hotspur football team, where he was for many years a season ticket holder.

[15] In 1950, Ayer attended the founding meeting of the Congress for Cultural Freedom in West Berlin, though he later said he went only because of the offer of a "free trip".

[17] Together with the historian Hugh Trevor-Roper, Ayer fought against Arthur Koestler and Franz Borkenau, arguing that they were far too dogmatic and extreme in their anti-communism, in fact proposing illiberal measures in the defence of liberty.

At a party that same year held by fashion designer Fernando Sanchez, Ayer confronted Mike Tyson, who was forcing himself upon the then little-known model Naomi Campbell.

[1] In 1988, a year before his death, Ayer wrote an article titled "What I saw when I was dead", describing an unusual near-death experience after his heart stopped for four minutes as he choked on smoked salmon.

Unless logical or empirical verification is possible, statements like "God exists" or "charity is good" are not true or untrue but meaningless, and may thus be excluded or ignored.

Ayer argues that moral judgements cannot be translated into non-ethical, empirical terms and thus cannot be verified; in this he agrees with ethical intuitionists.

… If now I generalise my previous statement and say, 'Stealing money is wrong,' I produce a sentence that has no factual meaning – that is, expresses no proposition that can be either true or false.

… I am merely expressing certain moral sentiments.Between 1945 and 1947, together with Russell and George Orwell, Ayer contributed a series of articles to Polemic, a short-lived British Magazine of Philosophy, Psychology, and Aesthetics edited by the ex-Communist Humphrey Slater.

[34] Ayer's formulation was that a sentence can be meaningful only if it has verifiable empirical import; otherwise, it is either "analytical" if tautologous or "metaphysical" (i.e. meaningless, or "literally senseless").

Ayer considered them completely unverifiable through empirical demonstration and logical analysis, and this sort of philosophy an unfortunate strain in modern thought.

In Philosophy in the Twentieth Century, Ayer accuses Heidegger of "surprising ignorance" or "unscrupulous distortion" and "what can fairly be described as charlatanism.

In the book's preface, he defends his selection to hold the lectureship on the basis that Lord Gifford wished to promote "natural theology, in the widest sense of that term", and that non-believers are allowed to give the lectures if they are "able reverent men, true thinkers, sincere lovers of and earnest inquirers after truth".

[39] He still believed in the viewpoint he shared with the logical positivists: that large parts of what was traditionally called philosophy—including metaphysics, theology and aesthetics—were not matters that could be judged true or false, and that it was thus meaningless to discuss them.

Ayer's sense-data theory in Foundations of Empirical Knowledge was famously criticised by fellow Oxonian J. L. Austin in Sense and Sensibilia, a landmark 1950s work of ordinary language philosophy.

[41] Ayer's biographer, Ben Rogers, deposited 7 boxes of research material accumulated through the writing process at University College London in 2007.