Professor Sir Michael Dummett, who has died aged 86, had a reputation as one of Britain’s most original and profound philosophers.

But he may be best remembered for the way he fought to stamp out racism.

In 1964, he and his wife Ann became concerned about racism and, with Evan Luard, Oxford’s former Labour MP, founded the Oxford Committee for Racial Integration, a forerunner for Oxfordshire Council for Community Relations.

He and five others were prosecuted under the 1965 Race Relations Act when they demonstrated against a Cowley Road ladies’ hairdressers, claiming it barred some customers because of the colour of their skin.

Oxford magistrates dismissed the charges, and Prof Dummett said: “It was quite funny. We were charged with displaying insulting signs likely to provoke a breach of the peace, and all our posters said was something like ‘fair treatment for all Oxford citizens’ – you couldn’t imagine anything milder.”

Prof Dummett was born in London in 1925 and was a first scholar at Winchester College from where he won a Major Scholarship in History at Oxford University’s Christ Church in 1943. He was unable to take up his place immediately and served in the Royal Artillery and Intelligence Corps from 1943 until 1947.

After being demobilised in 1947, he took a degree in Philosophy, Politics and Economics and was awarded a first in 1950.

His prize fellowship at All Souls College began a 29-year association with the college and after teaching in Birmingham for a year, he returned to Oxford.

He married Somerville College graduate Ann Chesney in 1951 and then began to develop his philosophical ideas, with his 1959 paper Truth, the most significant of his early works.

In 1962, he was appointed Reader in the Philosophy of Mathematics at Oxford University but apart from a short paper he read to the Aristotelian Society in 1969, he published nothing between 1965 and 1972 because he was devoting his time to combating racism. His work included driving to Heathrow Airport to make representations on behalf of immigrants refused entry to the country.

He became fascinated by tarot cards after his son got hold of a pack on holiday, which included the rules, and his fascination led to the publication of 600-page study The Game of Tarot in 1980.

By the 1970s, Prof Dummett felt able to focus again on philosophy and his first book came out, Frege: Philosophy of Language.

In 1979, he took up the Wykeham Chair of Logic at Oxford University and a sabbatical year at Stanford in 1988 gave him a chance to compile his Harvard lectures for 1991 publication The Logical Basis of Metaphysics.

He retired in 1992 but continued to live in Oxford and also continued to write, his final philosophical work, The Nature and Future of Philosophy, appearing in 2010.

Prof Dummett, who lived in Park Town, North Oxford, had seven children. He died on December 27 and is survived by his wife and five children.

His funeral is on Tuesday at St Aloysius Church, Woodstock Road, Oxford, at noon.