He was natural within Up to date Zealand. He became lecturer inside philosophy at Canterbury University College around 1945, then Prof in 1953. From either 1960 to 1966, he was a prof of philosophy at the University of Manchester, and within 1966 he gave the John Locke lectures in philosophy at a University of Oxford. From either 1966 until his dying he was Fellow & Coach within philosophy at Balliol College, Oxford.

He mass produced contributions two to the history of logic & to modern formal techniques. a important accomplishment was the foundation of tense logic. He as well mass produced significant contributions to intensional logic, particularly in the influential posthumous work Objects of Thought.