OXFORD University professor John Ackrill, a leader in the philosophical and scholarly study of Plato and Aristotle has died.

Born in Reading in 1921 and educated at Reading School, Professor Ackrill entered St John's College, Oxford, as a scholar in classics in 1940. The following year he left for war service in the Royal Berkshire Regiment and General Staff and reached the rank of captain.

He returned to Oxford in 1945 to read classics, philosophy, and ancient history. On graduation in 1948, Professor Ackrill went directly to a teaching position as assistant lecturer in logic at Glasgow.

He was appointed university lecturer at Oxford in ancient philosophy in 1949, but before he took up the post he was given two years of study leave, which he spent in Switzerland and in Princeton.

After two years as university lecturer, he became a tutorial fellow of Brasenose College in 1953.

In the same year he met and married his wife, Margaret Kerr, and the couple went on to have four children.

The pair set up their home in Charlbury Road, North Oxford.

In 1966, the university created a statutory chair in the history of philosophy and Professor Ackrill was elected the first holder.

He held it, while remaining a fellow of Brasenose, until his retirement in 1989.

He was elected a Fellow of the British Academy in 1981 and an Honorary Fellow of St John's in 1996.

John Peach, a Fellow at Brasenose and friend of Professor Ackrill, said: "He did not try to persuade a pupil of a particular doctrine, but tried to encourage critical thought through objections and replies.

"He was very good with students and went to great lengths with all of them and for that was wonderfully respected.

"All those who have been taught by him, will have memories of him being a very formidable, but helpful teacher and a high proportion of the leaders in his field today were taught by him."

Professor Ackrill passed away in Oxford on Friday, November 30.