He was born in Sydney, Australia, in 1917 and graduated from Oxford. He was a professor of political philosophy in Sydney and taught philosophy at the universities of Otago, Dunedin, New Zealand and York (England). From 1967 until his death in 1981 he was a member of the University of Oxford. In 1974 he also joined the British Academy as a member. His publications include Truth, Probability and Paradox (1973), The Cement of the Universe (1974), Problems from Locke (1976), Hume's Moral Theory (1980) and The Miracle of Theism (1982).