What interests me most are the metaphysical questions whose answers can affect our emotions, and have rational and moral significance. Why does the Universe exist? What makes us the same person throughout our lives? Do we have free will? Is time’s passage an illusion?

• On what matters, vol. 3. Oxford: Oxford University Press, 2017.
• Future people, the non–identity problem, and person-affecting principles, Philosophy & public affairs, vol. 45, no. 2 (Spring, 2017), pp. 118–157.
• Responses, in Simon Kirchin (ed.) Reading Parfit : On what matters, New York: Routledge, 2017, pp. 189–236.
• Conflicting reasons, Etica & politica, vol. 18, no. 1 (2016), pp. 169–186.
• Can we avoid the repugnant conclusion?, Theoria, vol. 82, no. 2 (May, 2016), pp. 110–127.
• Personal and omnipersonal duties, The Harvard review of philosophy, vol. 23 (2016), pp. 1–15.
• Another defence of the priority view, Utilitas, vol. 24, no. 3 (September, 2012), pp. 399–440.
• We are not human beings, Philosophy, vol. 87, no. 1 (January, 2012), pp. 6–28.
• On what matters, vol. 2. Oxford: Oxford University Press, 2011.
• On what matters, vol. 1. Oxford: Oxford University Press, 2011.
• Persons, bodies, and human beings, in Dean Zimmerman, Theodore Sider & John Hawthorne (eds.) Contemporary debates in metaphysics, Oxford: Blackwell, 2008, pp. 177–208.
• Is personal identity what matters?, The Ammonius Foundation, December 31, 2007.
• Kant’s arguments for his formula of universal law, in Christine Sypnowich (ed.) The egalitarian conscience : essays in honour of G. A. Cohen, Oxford: Oxford University Press, 2006, pp. 56–69.
• Normativity, in Russ Shafer-Landau (ed.) Oxford studies in metaethics, vol. 1, Oxford: Clarendon Press, 2006, pp. 325–380.
• Postscript, in Jesper Ryberg & Torbjörn Tännsjö (eds.) The repugnant conclusion : essays on population ethics, Dordrecht: Kluwer, 2004, p. 257.
• Justifiability to each person, Ratio, vol. 16, no. 4 (December, 2003), pp. 368–390.
• What we could rationally will, The Tanner lectures on human values, 2002.
• Rationality and reasons, in Dan Egonsson, Jonas Josefsson, Björn Petterson & Toni Rønnow-Rasmussen (eds.) Exploring practical philosophy : from action to values, Aldershot: Ashgate, 2001, pp. 17–39.
• Bombs and coconuts, or rational irrationality, in Christopher W. Morris & Arthur Ripstein (eds.) Practical rationality and preference : essays for David Gauthier, New York: Cambridge University Press, 2001.
• Experiences, subjects, and conceptual schemes, Philosophical topics, vol. 26, nos. 1–2 (Spring/Fall, 1999), pp. 217–270.
• Why anything? Why this?, London review of books, vol. 20, no. 3 (February 5, 1998), pp. 22–25.
• Why anything? Why this?, London review of books, vol. 20, no. 2 (January 22, 1998), pp. 24–27.
• Equality and priority, Ratio, vol. 10, no. 3 (December, 1997), pp. 202–221.
• Reasons and motivation, Supplementary volume – Aristotelian Society, vol. 71 (1997), pp. 99–130.
• Acts and outcomes: a reply to Boonin-Vail, Philosophy & public affairs, vol. 25, no. 2 (Fall, 1996), pp. 308–317.
• The unimportance of identity, in Henry Harris (ed.) Identity : essays based on Herbert Spencer lectures given in the University of Oxford, New York: Clarendon Press, 1995, pp. 13–45.
• An Interview with Derek Parfit, Cogito, vol. 9, no. 2 (August, 1995), pp. 115–125.
• The indeterminacy of identity: a reply to Brueckner, Philosophical studies, vol. 70, no. 1 (April, 1993), pp. 23–33.
• Paul Seabright: pluralism and the standard of living, in Martha Nussbaum & Amartya Sen (eds.) The quality of life, Oxford: Oxford University Press, 1993, pp. 410–417.
• Who do you think you are?, Times higher education supplement (December 11, 1992), pp. 19–20.
• The puzzle of reality: why does the universe exist?, Times literary supplement (July 3, 1992), pp. 3–5.
• Against the social discount rate, in Peter Laslett & James S. Fishkin (eds.) Justice between age groups and generations, New Haven: Yale University Press, 1992, pp. 144–161. (with Tyler Cowen)
• Isaiah Berlin, Times literary supplement (July 19, 1991), p. 13.
• Why does the universe exist?, The Harvard review of philosophy, vol. 1, no. 1 (Spring, 1991), pp. 2–5.
• On giving priority to the worse off, unpublished MS (ca. 1991).
• Equality or priority? : the Lindley lecture. Kansas: University of Kansas, 1991.
• What we together do, unpublished MS (March 29, 1988), 33 pp.
• A response, in Arthur Peacocke & Grant Gillett (eds.), Persons and personality: a contemporary inquiry, Oxford: Basil Blackwell, 1987, pp. 88–98.
• A reply to Sterba, Philosophy & public affairs, vol. 16, no. 2 (Spring, 1987), pp. 193–194.
• Divided minds and the nature of persons, in Colin Blakemore & Susan Greenfield (eds.) Mindwaves : thoughts on intelligence, identity and consciousness, Oxford: B. Blackwell, 1987, pp. 19–28.
• Comments, Ethics, vol. 96, no. 4 (July, 1986), pp. 832–872.
• Overpopulation and the quality of life, in Peter Singer (ed.) Applied ethics, Oxford: Oxford University Press, 1986, pp. 145–164.
• Rationality and time, Proceedings of the Aristotelian Society, vol. 84 (1984), pp. 47–82.
• Reasons and persons. Oxford: Clarendon press, 1984.
• Energy policy and the further future: the social discount rate, in Douglas MacLean & Peter G. Brown (eds.) Energy and the future, Totowa, New Jersey: Rowman and Littlefield, 1983, pp. 31–37.
• Energy policy and the further future: the identity problem, in Douglas MacLean & Peter G. Brown (eds.) Energy and the future, Totowa, New Jersey: Rowman and Littlefield, 1983, pp. 166–179.
• Summary of discussion, Synthese, vol. 53, no. 2 (November, 1982), pp. 251–256. (with Daniel Dennett, Donald Regan, Richard Rorty, Alasdair MacIntyre, Harry Frankfurt, Annette Baier & Jim Doyle)
• Personal identity and rationality, Synthese, vol. 53, no. 2 (November, 1982), pp. 227–241.
• Future generations: further problems, Philosophy & public affairs, vol. 11, no. 2 (Spring, 1982), pp. 113–172.
• Correspondence, Philosophy & public affairs, vol. 10, no. 2 (Spring, 1981), pp. 180–181.
• An attack on the social discount rate, Philosophy & public policy quarterly, vol. 1, no. 1 (1980), pp. 8–11.
• Is common-sense morality self-defeating?, The journal of philosophy, vol. 76, no. 10 (October, 1979), pp. 533–545.
• Correspondence, Philosophy & public affairs, vol. 8, no. 4 (Summer, 1979), pp. 395–397.
• Prudence, morality, and the prisoner’s dilemma, Proceedings of the British Academy, vol. 65, (1979), pp. 539–564.
• Innumerate ethics, Philosophy & public affairs, vol. 7, no. 4 (Summer, 1978), pp. 285–301.
• Lewis, Perry, and what matters, in Amélie Rorty (ed.) The identities of persons, University of California Press: Berkeley, 1976, pp. 91–107.
• On doing the best for our children, in Michael D. Bayles (ed.) Ethics and population, Cambridge, Massachusetts: Schenkman Pub. Co., 1976, pp. 100–115.
• Rights, interests, and possible people, in Samuel Gorovitz, Andrew L. Jameton, Ruth Macklin, John M. O’Connor, Eugene V. Perrin, Beverly Page St. Clair & Susan Sherwin (eds.) Moral problems in medicine, Englewood Cliffs, N.J.: Prentice-Hall, 1976, pp. 369–375.
• Later selves and moral principles, in Alan Montefiore (ed.) Philosophy and personal relations : an Anglo-French study, London: Routledge & Kegan Paul, 1973, pp. 137–169.
• On “The importance of self-identity”, The journal of philosophy, vol. 68, no. 20 (October, 1971), pp. 683–690.
• Personal identity, The philosophical review, vol. 80, no. 1 (January, 1971), pp. 3–27.
• The Eton College chronicle, in Cheetham & Parfit, Eton microcosm, pp. 100–103.
• The fish, in Cheetham & Parfit, Eton microcosm, pp. 182–183.
• Eton microcosm. London: Sidgwick and Jackson, 1964. (with Anthony Cheetham)
• Like pebbles, ISIS (March 13, 1963), pp. 21–22.
• Photograph of a Comtesse, The New Yorker (June 23, 1962), p. 24.

With thanks to David Edmonds, Johan Gustafsson, and Matthew van der Merwe.

What now matters most is how we respond to various risks to the survival of humanity. We are creating some of these risks, and we are discovering how we could respond to these and other risks. If we reduce these risks, and humanity survives the next few centuries, our descendants or successors could end these risks by spreading through this galaxy.

Life can be wonderful as well as terrible, and we shall increasingly have the power to make life good. Since human history may be only just beginning, we can expect that future humans, or supra-humans, may achieve some great goods that we cannot now even imagine. In Nietzsche’s words, there has never been such a new dawn and clear horizon, and such an open sea.