AYER, Sir Alfred Jules (1910-89), British philosopher, who influenced the development of contemporary analytic philosophy. He taught at the universities of Oxford and London and became Wykeham Professor of Logic at Oxford in 1959. Ayer's book Language, Truth, and Logic (1936) was an influential expression of logical positivism. Other works of Ayer include The Problem of Knowledge (1956), The Central Questions of Philosophy (1973), and Part of My Life: The Memoirs of a Philosopher (1977).