Derek Parfit died on 2 January 2017. He was a philosopher, whose work focused on personal identity, the basis of ethics, and our obligations to future beings. The title of his 2011 book states his overall focus: On What Matters. He was a distinctive person, and he produced strikingly original and influential work.
I was a final year BA student in philosophy at the University of Canterbury when Parfit published his first book in 1984. Seven years later he was an examiner of my Oxford D.Phil. thesis. He gave me a fair grilling and a fair go.
He was born on 11 December 1942 in Chengdu, China, the second of the three children of Jessie and Norman Parfit. Jesse and Norman practised preventive medicine in Christian missionary hospitals. Soon after Derek’s birth they moved back to the UK. Derek’s school record was outstanding in every subject except mathematics. He ‘read’ for a Bachelor of Arts (BA) in history at Balliol College, Oxford, 1961-64. Seven years after they get their BA, Oxford BA graduates are awarded the degree of Master of Arts. That was his highest degree. Following a period in the USA as a Harkness Fellow, in 1967 he won a Prize Fellowship to All Souls College, Oxford. It remained his primary academic base. In 1983 or so, Parfit met Janet Radcliffe Richards, author of the 1980 book The Sceptical Feminist. They got together some months later, and were together for the rest of his life.
Parfit published little between his first paper in 1971 and his 1984 book Reasons and Persons. It also took some pushing to get him to publish that book. In the last ten years of his life, he published two large and densely argued volumes of On What Matters (2011). Its ‘critics and responses’ volume three (2017) was published a couple of weeks after he died. Just two books, but ideas, arguments, and implications enough to outrun at least a dozen regular books.
The Parfit sentence is short, spare, and declarative. It also expresses his unquenchable appetite for examples, refinements, criticisms, replies, and rejoinders. His work deploys a lot of thought experiments, many science-fictional, but all intended to be possible and thereby on point. His writing often has somewhat mathematical structure. One Appendix is titled ‘Five mistakes in moral mathematics’. His work was much of his life, yet his attachments were to its content, justification, and prospects in the world, not to its author. Also legendary was the intellectual generosity of his responses to the work of others. To beginner undergraduates, as much as to senior colleagues, his comments were hugely helpful and typically as lengthy as their work was. Though he did engage very sympathetically when in direct contact with people, Parfit was nevertheless more of a persons person than a people person. He personified the life of the mind.
He argued that personal identity over time is a matter of psychological continuities, not a matter of the body, human being, or human animal. Psychological continuity, not personal identity, is also what matters to ethics, to good reasons for action, and to finding an apt attitude toward one’s own death. He made many ingenious arguments for these claims. If true, those claims of his are significant for and in many domains. For example, they would destabilise self-interest theories of morality, rationality, and much else, by undermining the self that these theories aggrandise. His claims would also undermine the following familiar question, and a legion of answers to it: What does it mean to be human? The title of a 2012 Parfit paper asserts: “We are not human beings”. We are instead clusters of psychological states, within the human or other frames that happen now to embody or materialize those states.
Parfit regarded the Victorian moral philosopher Henry Sidgwick as “my dull hero”, and The Methods of Ethics (1874/1907) as the greatest work of moral philosophy since Aristotle. Sidgwick’s book is a thorough and self-doubting attempt to reconcile the ‘methods’ of commonsense morality, egoism, and utilitarianism. Parfit is deeply and deliberately Sidgwickian. For instance, On What Matters includes a thorough and assertive attempt to reconcile Kant’s ethics with Scanlon-style contractualism and Hooker-style rule consequentialism. Parfit argues that these are the best three climbers, all ascending the one ethical mountain, and his own ‘triple theory’ that synthesises and improves these three is the best current account of what is to be found at the summit.
Parfit argued for many other ideas too. One is the objectivist thesis that certain things are good, and give us reasons to care about them, whether or not we desire those things. Our desires are answerable to the good of things, not vice versa. Another is that the best egalitarianism pursues priority to those worse off, rather than equality. A third is that future people and generations are vital to ethics; almost all ethical theories make a hash of this, and it is also hard to work out any satisfactory account here. Tim Mulgan, Otago philosophy graduate, student of Parfit, and now professor at the University of Auckland, is an expert in this field.
Parfit’s voice leads on so many topics. For instance, he wrote an Appendix on ‘What makes someone’s life go best’. That’s my research specialty. When I have a new idea about it, I often find it there already in Parfit. Parfit has also connected well beyond philosophy. Larissa MacFarquhar’s 2011 profile for The New Yorker is a wonderful account of the person and the work. Derek Parfit is dead, but he has many psychological continuities.
Andrew Moore is Associate Professor in Philosophy at the University of Otago, Dunedin, New Zealand.