Professor Sir Michael Dummett: Philosopher and anti-racism campaigner

Dummett with his wife Ann and their five children; Ann worked alongside him in their fight against racism

Professor Sir Michael Dummett was one of the most important philosophers of the English speaking world in the second half of the 20th century. Wykeham Professor of Logic in the University of Oxford, he was enormously influential through major publications and supervision of many outstanding graduate students. He also played a significant role combatting racism, and when he was knighted it was "for Services to Philosophy and to Racial Justice". He was a world authority on voting procedures, a study of the problem of ensuring fair results as free as possible from distortion by tactical voting.

Brought up in an irreligiously Anglican family, and an atheist at 13, he converted to Catholicism at 18 and remained deeply religious to the end of his life. He pursued a passionate interest in the games played with tarot cards, and in the cards themselves, and published studies which have transformed understanding of the history of tarot. He also loved jazz, and was proud to have heard Billie Holiday sing (in 1956).

Michael Anthony Eardley Dummett was born in London in 1925. His father, George Dummett, was a silk merchant, his mother, Iris née Eardley-Wilmont, the daughter of a colonial administrator. Dummett began his secondary education in September 1939 as a Scholar at Winchester College. After a year on the classics ladder, he opted for science, then switched to history.

In 1943 he obtained a history scholarship to Christ Church, Oxford, but went instead into the Royal Artillery and was sent on a six-month course in Edinburgh. While there he was received into the Catholic Church. After Basic Training he was transferred to the Intelligence Corps and sent to Bedford for a six-month course of training to translate written Japanese, and then to the Wireless Experimental Centre outside Delhi, in which intercepted Japanese messages were translated.

When the war ended, Dummett was sent to Malaya as part of Field Security. He wrote recently that "it must have been in Malaya that a passionate hatred of racism was first born in me. I learned of the means by which the British masters of pre-war colonial Malaya had maintained and acted out the myth of white racial superiority", though Michael Screech remembers Dummett expressing anger about racism already while on the Bedford course and at the Wireless Centre.

He was demobilised in 1947, just in time to go up to Christ Church that year. He felt he had forgotten much of the history he had learnt, and chose instead to read Philosophy, Politics and Economics (PPE). He was "soon captivated by philosophy". In Finals he took a newly established paper in which candidates were expected to study four texts from a list of seven, one of which was Frege's Grundlagen der Arithmetik, recently translated by JL Austin for this purpose. Dummett said later, "I thought, and still think, that it was the most brilliant piece of philosophical writing of its length ever penned." His lifelong study of Frege's philosophy has transformed our understanding of Frege.

After receiving a First, Dummett was appointed to a one-year assistant lectureship at the University of Birmingham. He also sat the Fellowship examination at All Souls College and was elected, but he fulfilled his commitment to Birmingham, rushing back to Oxford throughout the term.

The first project Dummett set himself as a Prize Fellow at All Souls was to read all Frege's published work, most of which had been neither translated nor republished. He also visited the Frege archive in Münster to study what survived of Frege's unpublished work. Despite his passion for Frege, Dummett began by thinking of himself as a follower of Wittgenstein, arising from the impact of the arrival in Oxford during his last year as an undergraduate of typescripts of The Blue and Brown Books and of notes of Wittgenstein's classes on philosophy of mathematics, and his philosophical contact and developing friendship with his tutor Elizabeth Anscombe. By 1960 he no longer considered himself a Wittgensteinian.

In 1951 he married Ann Chesney, who had taken just finals in History from Somerville. In 1955 he was awarded a Harkness Fellowship to spend a year at Berkeley studying logic and mathematics. He came to know Donald Davidson, at Stanford; they remained friends and philosophical interlocutors.

In 1958 Dummett spent a term at the University of Ghana, lecturing on the philosophy of time. In 1959 he published Truth, a seminal work and his most important single paper, which contains the seeds of all his later philosophy. It adumbrates the opposition between realism and anti-realism, as Dummett characterises these positions, and surveys a variety of contexts in which this opposition arises. Mathematical intuitionism is cited as a paradigm of anti-realism, but on a basis different from that of LEJ Brouwer, intuitionism's founder. A connection between these considerations and Wittgenstein's dictum that meaning is use is sketched.

This is a heady mixture of ideas which have taken decades to explore. In a Postcript to that paper in 1972 he wrote that the dispute between realism and anti-realism "is still a long way from resolution. On the one hand, it is unclear whether the realist's defence of his position can be made convincing; on the other, it is unclear whether the anti-realist's position can be made coherent. I remain convinced, however, that the issue between realism and anti-realism, construed roughly along the present lines, is one of the most fundamental of all the problems of philosophy."

In 1962 Dummett was appointed to the Oxford University Readership in Philosophy of Mathematics. In 1964 he accepted a visiting appointment at Stanford, giving a course attempting to survey every variety of realism and anti-realism, which he planned to develop into a book that would realise the programme of his Truth paper, but came to accept he would never complete.

When he returned to Oxford in 1964, he and Ann decided "the time had come for organised resistance to the swelling racism in England". For the next four years Dummett devoted himself to the fight against racism while keeping up with his teaching. He and Ann worked both to help individuals and to establish and strengthen organisations to combat racism as a trend in British government and society. He played a key role in founding the Joint Council for the Welfare of Immigrants in 1967.

A graduate student newly arrived in 1967 and keen to discuss Truth with him recalls Dummett being available even while devoting himself to the fight against racism. A telephone call in the midst of discussing philosophy would inform Dummett that an East-African Asian attempting to enter Britain was about to be sent back, and transform Dummett from philosopher to activist, dashing to the airport to argue the case. He described this time as "the most exhausting period of my life".

During this time Dummett continued to be an inspiring teacher and played a key role in establishing mathematical logic at Oxford. This resulted in a Lecturership in Mathematical Logic, an undergraduate course in Mathematics and Philosophy and a Professorship in Mathematical Logic.

The period in which Dummett gave the fight against racism highest priority lasted until spring 1968, when he spent a term at the University of Minnesota. Back at Oxford he returned to philosophy, working on Frege: Philosophy of Language, published in 1973. In the Preface he explains: "The alienation of racial minorities is now so great that a white ally in the struggle can, except in special circumstances, play only the most minor ancillary part."

Dummett was elected to a Senior Research Fellowship at All Souls in 1974. In 1976 he gave the William James Lectures at Harvard, on "The Logical Basis of Metaphysics". In 1977 he published Elements of Intuitionism, a remarkable accomplishment. Pedagogically, it's a textbook of intuitionist mathematics and logic, which played an important part in making intuitionism accessible to study. Mathematically, it contains new results about intuitionism on many topics,. Philosophically it is extremely important, in establishing that intutionist mathematics and logic can be cast in the form of Dummettian anti-realism, and in this way has an integral place in the pursuit of Dummett's philosophical programme from Truth. In 1979 he gave up his Senior Research Fellowship at All Souls to accept election as Wykeham Professor of Logic and Fellow of New College. He was now in huge demand as a graduate supervisor, and often was called upon to supervise as many as 15 students at a time.

In 1982 Dummett was awarded an Alexander von Humboldt-Stiftung Research Prize, which he used to work on his book Frege: Philosophy of Mathematics at the University of Münster. In 1988-89 he spent the year in Stanford as a Fellow of the Center for Advanced Study in the Behavioral Sciences. In this, his only full year of sabbatical leave, he finished two books, Frege: Philosophy of Mathematics, and The Logical Basis of Metaphysics.

Dummett retired from Oxford in 1992 and was knighted in 1999. He gave many lectures in retirement, including the Gifford Lectures at St Andrews in 1997 and the John Dewey Lectures at Columbia in 2003. He was elected a Senior Fellow of the British Academy in 1995 and received many other honours, including the Lakatos Prize in 1994, the Rolf Schock Prize in 1995, and the Lauener Prize in 2010, and various honorary degrees. His last major publication, Thought and Reality, in 2006, was a reworking of his Gifford Lectures. One can wonder how Dummett was able to pursue so many disparate interests to such great accomplishment in each. Part of an answer must be that he had an extraordinary facility at written expression: the speed with which he composed at a typewriter was audibly that of an efficient copy typist.

Everyone who knew Dummett has vivid memories of his smoking, which for most of his life he did using a short cigarette holder, tapping the end of his cigarette so many times before lighting it that this action came to be called "dummetting" by those around him.

Dummett's philosophy lives on not only in his publications but in the many critical discussions of it, including eight books devoted to his philosophy, among them the ultimate accolade, a volume in the Library of Living Philosophers.

Michael Anthony Eardley Dummett, philosopher and anti-racism activist: born London 27 June 1925; Wykeham Professor of Logic, University of Oxford 1979–92, Professor Emeritus 1992; Emeritus Fellow, All Souls College, Oxford, 1979; Kt 1999; married 1951 Ann Chesney (three sons, two daughters, one son deceased and one daughter deceased); died 27 December 2011.

* For a fuller version of this obituary see here