As an undergraduate, Donald Gillies studied Mathematics and Philosophy at Cambridge. In 1966 he began graduate studies in Professor Sir Karl Popper's department at the London School of Economics, and he completed his PhD on the Foundations of Probability in 1970 with Professor Imre Lakatos as supervisor. From 1968 to 1971, he was a Fellow of King's College, Cambridge. In 1971 he joined the staff of the University of London, and is at present Reader in History and Philosophy of Science at King's College London. In 1982, he was a Visiting Scholar at Harvard University, and from 1982 to 1985 edited the British Journal for the Philosophy of Science.