Sir Alfred Jules Ayer (October 29, 1910 – June 27, 1989), better known as A. J. Ayer (or Freddie by his friends), was a British philosopher known for his promotion of logical positivism, particularly in his books Language, Truth and Logic (1936) and The Problem of Knowledge (1956).
Ayer was the Grote Professor of the Philosophy of Mind and Logic at the University College London from 1946 until 1959, when he became Wykeham Professor of Logic at Oxford University. He was knighted in 1970.
He taught or lectured several times in the United States, including serving as a visiting professor at Bard College in the fall of 1987. At a party that same year held by fashion designer Fernando Sanchez, Ayer, then 77, confronted Mike Tyson harassing Naomi Campbell and demanded that Tyson stop. Tyson said: "Do you know who the fuck I am? I'm the heavyweight champion of the world," to which Ayer replied: "And I am the former Wykeham Professor of Logic. We are both pre-eminent in our field. I suggest that we talk about this like rational men." (Rogers, 344)
Ayer was educated at Eton College, and served in the British military during World War II.
He was married four times, including to Dee Wells and Vanessa Lawson (nee Salmon).
Ayer was closely associated with the British humanist movement. He was an Honorary Associate of the Rationalist Press Association from 1947 until his death. In 1965, he became the first president of the Agnostics' Adoption Society and in the same year succeeded Julian Huxley as president of the British Humanist Association, a post he held until 1970. In 1968 he edited "The Humanist Outlook", a collection of essays on the meaning of humanism.
Shortly before his death in 1989 he received publicity after having an unusual near-death experience, which to some suggested that he had moved away from his lifelong and famous religious skepticism.
In some ways, Ayer was the philosophical successor to Bertrand Russell, and he wrote two books on the philosopher: Russell and Moore: The Analytic Heritage (1971) and Russell (1972). He also wrote an introductory book on the philosophy of David Hume.
He is perhaps best known for his verification principle, an attempt at
creating a process for determining whether a sentence has any logical meaning.
In 1972-73 Ayer gave the Gifford Lectures at St. Andrews University, later
published as The Central Questions of Philosophy. He still believed in the
viewpoint he shared with the logical positivists: that large parts of what was
traditionally called "philosophy" - including the whole of metaphysics, theology
and aesthetics - were not matters that could be judged as being true or false
and that it was thus meaningless to discuss them. Unsurprisingly, this made him
unpopular with several other philosophy departments in this country and his name
is still reviled by many British professors to this day.
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 1950's work of common language philosophy. Ayer responded to this in the essay "Has Austin refuted the sense-date theory?"
In "The Concept of a Person and Other Essays" (1963), Ayer made several striking criticisms of Wittgenstein's private language theory.