By Richard Pearson
Washington Post Staff Writer
Wednesday, June 18, 2003; Page B06

Sir Bernard Williams, 73, a witty, learned and combative British philosopher who was known for his work in moral philosophy, questions of moral identity, the history of philosophy and the nature of truth, died June 10 while vacationing in Rome. He had cancer.

Over the years, in a series of pioneering and densely argued books, he explained early Greek ethical philosophy and the works of Descartes and analyzed Kantian ethics and Utilitarianism. His works on moral philosophy, which drew on political theory, history and metaphysics, resulted in his being hailed by many as the greatest British philosopher of his time.

His books included "Descartes: The Project of Pure Enquiry" (1978), "Moral Luck" (1981), "Ethics and Limits of Philosophy" (1985), "Shame and Necessity" (1993) and "Truth and Truthfulness" (2002).

In addition to a life as a philosopher and professor at such institutions as Oxford, Cambridge and London universities, Sir Bernard led a public life. He chaired and served on royal commissions and government and Labor Party committees.

In the late 1970s, he chaired a government Committee on Obscenity and Film Censorship, whose 13 members included a psychologist, a police officer, a lawyer, a bishop, a schoolteacher and a newspaper film critic.

In its obituary of Sir Bernard, The Times of London newspaper quoted him as explaining, "I did all the major vices -- gambling, drugs, pornography and public schools."

Bernard Arthur Owen Williams was a native of Essex, England, and a 1951 graduate of Oxford University's Balliol College.

He then spent what he always maintained were the happiest years of his life, flying fighter planes with the Royal Air Force in Canada. In later years, he enjoyed driving sports cars.

After his military service, he returned to Oxford, where he taught until 1959. He later taught at the University of London, was a moral philosophy professor and provost at Cambridge and again returned to Oxford, where he was an honorary fellow of Balliol at the time of his death.

Over the years, he had been a visiting professor in Africa and Australia and taught in the United States at Princeton and Harvard universities, as well as the University of California at Berkeley.

Sir Bernard, who was knighted in 1999, was a fellow of the British Academy and an honorary member of the American Academy of Arts and Sciences. He served on the board of the English National Opera and wrote extensively about music, including the entry for "opera" in the Grove music dictionary.

In 1955, he married Shirley Brittain. As Shirley Williams, she became a Labor Party cabinet minister before breaking with the party to help found the Social Democratic Party. As Baroness Williams of Crosby, she became a leader of the Liberal Democrats in the House of Lords.

The marriage was dissolved in 1974 and later annulled. Also in 1974, Sir Bernard married Patricia Law Skinner. She survives him, as do their two sons and a daughter from his first marriage.