Derek Parfit 1942 – 2017

Derek Parfit was a British philosopher widely regarded as one of the most important moral philosophers of the late twentieth century. A long-serving senior research fellow at All Souls College, Oxford, he devoted the better part of three decades to a single book, Reasons and Persons, published in 1984, and a further long labour to On What Matters, published in two volumes in 2011 with a third appearing posthumously. He defended a reductionist account of personal identity, an exacting consequentialism, and the convergence of the great ethical theories on a common core. His careful moral arguments and famous puzzle cases have shaped ethics, population theory, and the philosophy of personal identity.

Derek Antony Parfit was born in 1942 in Chengdu, in western China, where his English parents were medical missionaries. The family returned to Britain in 1944, and he was educated at Eton and at Balliol College, Oxford. After a year as a Harkness Fellow at Columbia and Harvard, he was elected in 1967 to a fellowship at All Souls College, Oxford, which he held until his death.

He wrote slowly and revised endlessly. His major works are Reasons and Persons (1984) and the two volumes of On What Matters (2011) — to which a third, partial volume was added posthumously in 2017 — supplemented by a small number of essays of extraordinary density. Reasons and Persons examines self-interest theory, personal identity, future generations, and the rationality of morality through a series of carefully constructed thought experiments; On What Matters defends a non-naturalist objective morality and tries to show that the great Kantian, contractualist, and consequentialist traditions can converge on something like a 'triple theory' of ethics.

Parfit's reductionist view of personal identity, his demonstration that questions of identity over time can matter less than questions of psychological continuity, his careful analyses of population ethics and the non-identity problem, and his unembarrassed defense of the objectivity of value made him one of the most influential moral philosophers of his generation. He died in London in January 2017.