AYER Alfred Jules—one of the main representatives of British logical positivism, b. 1910 in London, d. in London in 1989.
Ayer was educated in Eton and Oxford. With Ryle’s encouragement he went to Vienna in 1932, where he had meetings with the Vienna Circle and took up the doctrine of logical positivism. In 1933 he received the position of lecturer in philosophy in Oxford’s Christ Church. During World War II he served in military intelligence. In 1945 he returned to Oxford as a fellow of Wadham College and also was dean. From 1946 to 1959 he held the prestigious position of professor of logic and philosophy of mind at University College in London. From 1959 to 1978 he was professor of logic in New College in Oxford. From 1978 to 1983 he was a fellow of Wolfson College and a member of the British Academy. In 1970 he was knighted.
Ayer’s views place him in the tradition of British empiricism, which began with Locke and Hume, and was continued by Russell. Ayer is the author of many significant works, including the following: Language, Truth and Logic (Lo 1936, 19462; The Foundation of Empiricial Knowledge, (Lo 1940); Thinking and Meaning, (Lo 1947); Philosophical Essays, (Lo 1954); The Problem of Knowledge (Lo 1956; Problem poznania [Problem of cognition], Wwa 1965); The Concept of a Person and Other Essays (Lo 1963); The Origins of Pragmatism. Studies in the Philosophy of C. S. Peirce and W. James (Lo 1968); Metaphysics and Common-Sense (Lo 1969); Russell and Moore: The Analytical Heritage, (Lo 1971); Probability and Evidence (Lo 1972); Bertrand Russell (Lo 1972); The Central Questions of Philosophy (Lo 1973); Hume (Ox 1980); Philosophy in the Twentieth Century, (Lo 1982); Freedom and Morality and Other Essays, (Ox 1984). Posthumously an edition of uncompleted texts was published: The Meaning of Life and Other Essays (Lo 1990). He also published two autobiographies: Part of my Life (Lo 1977), and More of my Life (Lo 1984).
Ayer’s first book, Language, Truth and Logic, is regarded as a classical presentation of British logical positivism. Its main thesis states that all cognitively meaningful propositions are either analytic and a priori (true or false by virtue of the rules of langauge), or synthetic and a posteriori, and so empirically verifiable. Analytic a priori propositions include the propositions of logic and mathematics. Synthetic a posteriori propositions include scientific statements and statements of facts. Ayer thought that a proposition is strongly verifiable if its truth (or falsehood) can be conclusively established by experience, and a proposition is weakly verifiable if by experience the proposition becomes more probable. His acceptance of the verification theory of meaning allowed Ayer to deny the meaningfulness of all metaphysical assertions, sine they are neither propositions of logic, nor empirically testable propositions. This applies also to propositions stating or rejecting the existence of God. The task of philosophy is not to investigate what things are true, but the logical analysis of scientific concepts. Ayer developed the consequences of the verification theory of meaning and proposed a reductionistic analysis of the self, the external world, and other minds. Propositions about physical objects can be translated into propositions about sense experiences. This position is thus a certain kind of phenomenalism. Ayer also rejected the existence of necessity in nature, since he regarded “necessity” as a purely logical concept. He interpreted causality as the regularity (correlation) of events. He regarded propositions concerning other minds as meaningful because they are verifiable through data concerning behavior. There are no such data in the case of propositions concerning one’s own mind. Mental predicates thus mean something else, depending upon whose mind the analyzed propositions concern. Value statements and moral statements, however, should be recognized as meaningless and lacking qualifications for truth and falsehood, since they do not meet the criterium of empirical verifiability. They can be analyzed only as expressions of emotion or attitudes toward a particular action. This position is called emotivism.
Ayer remained faithful to most of his theses, especially the fundamental ideas of the verification theory of meaning. In the second edition of Language, Truth and Logic he gave the principle of verification a much more cautious and more precise formulation: a proposition is immediately verifiable is either it is a proposition of observation (i.e., a report of a particular individual observation), or in conjunction with other propositions of observation it implies a proposition that cannot be inferred from these propositions alone. A proposition is indirectly verifiable if, in conjunction with others, it implies an immediately verifiable proposition, while these propositions taken as premises must be either analytic propositions, or immediately verifiable, or independently and indirectly verifiable. In his critique of Ayer, Church showed that this formulation allows us to recognize as meaningful metaphysical propositions, the elimination of which the principle of verification was intended to serve. Ayer remained faithful as well to the empiricist version of foundationalism, although in relation to Language, Truth and Logic he modified his views on the nature of the propositions that form the basis of empirical knowledge. Ayer rejected the conventionalism proposed by some members of the Vienna Circle and thought that the foundation of knowledge is made up of propositions concerning sensory experiences, since these register only what was experienced without at the same time implying anything about what might be true. These propositions may perform the role of base propositions, even if they are fallible. The only essential fact is that they cannot be false in the way way in which propositions concerning physical objects may be false.
In his later works, Ayer rejected the simple phenomenalism presented in Language, Truth and Logic and in The Foudation of Empirical Knowledge in favor of a refined realism in the question of physical objects. Ayer explicitly distinguished this refined realism from naive realism, which recognizes the direct perception of physical objects. According to this position, expressed in final form in The Central Questions of Philosophy, although the data of experience occupy a privileged cognitive position, the existence of physical objects is postulated in order to explain the coherence and non- contradiction of these experiences. Certain neutral sensory contents, which Ayer calls “qualia” are the basis of our perceptual judgments. “Qualia” appear in the person’s field of sensory experience and are transformed into individual “percepts”. Ayer called this the original system. These contents form certain regularities in time and space, on the basis of which we create a secondary system, the theory of the “visual-factual continuum”. The empirical basis is then interpreted as a set of states of the perceiving subject. They are causally conditioned by the postulated physical objects.
In The Problem of Knowledge, Ayer developed a conception of knowledge as true and rationally justified beliefs. At the same time he took up a discussion with skepticism. According to Ayer, person X knows that p, if: (1) p is true; (2) X is certain that p, and (3) X has the right to be certain that p. These three conditions are necessary and sufficient to recognize p as knowledge. The above thesis was refuted by E. Gettier who presented examples of beliefs that meet the conditions Ayer mentions but cannot be recognized as knowledge. Ayer did not acknowledge that his analysis was wrong, only that the concept of rational justification is more complicated than he originally thought.
Ayer also remained faithful to emotivism. He complemented his original view with the thesis that propositions expressing an attitude toward an action contain a prescriptive element: a positive moral judgment not only expresses a favorable disposition toward an action, but also encourages others to adopt this same attitude. Ayer explicitly stated that these judgments do not concern a positive act (e.g., this particular murder), but a whole class (murder as such).
M. Hempoliński, Brytyjska filozofia analityczna [British Analyitic Philosophy], Wwa 1974; Perception and Identity, Lo 1979; J. Foster, Ayer, Lo 1985; Fact, Science, and Morality, Ox 1986; A. J. Ayer: Memorial Essays, Lo 1991; T. Honderich, Essays on A. J. Ayer, C 1991; The Philosophy of A. J. Ayer, La Salle 1992; M. Hempoliński, PLF IV 26–40; B. Rogers, A. J. Ayers, A Life, Lo 1999.