Derek Parfit, who died in 2017, is widely believed to have been the most significant moral philosopher in well over a century. The twenty-one new essays in this book have all been inspired by his work. They address issues with which he was concerned in his writing, particularly in his seminal contribution to moral philosophy, Reasons and Persons (OUP, 1984). Rather than simply commenting on his work, these essays attempt to make further progress with issues, both moral and prudential, that Parfit believed matter to our lives: issues concerned with how we ought to live, and what we have most reason to do. Topics covered in the book include the nature of personal identity, the basis of self-interested concern about the future, the rationality of our attitudes toward time, what it is for a life to go well or badly, how to evaluate moral theories, the nature of reasons for action, the aggregation of value, how benefits and harms should be distributed among people, and what degree of sacrifice morality requires us to make for the sake of others. These include some of the most important questions of normative ethical theory, as well as fundamental questions about the metaphysics of personhood and personal identity, and the ways in which the answers to these questions bear on what it is rational and moral for us to do.

Jeff McMahan, University of Oxford,Tim Campbell, Institute for Futures Studies, Stockholm,James Goodrich, Rutgers University and University of Stockholm,Ketan Ramakrishnan, Yale Law School and the University of Oxford

Jeff McMahan is White's Professor of Moral Philosophy at the University of Oxford. He is the author of The Ethics of Killing: Problems at the Margins of Life (OUP, 2002) and Killing in War (OUP, 2009).

Tim Campbell is a researcher at the Institute for Future Studies at the University of Stockholm.

James Goodrich is a PhD student in philosophy at Rutgers and Stockholm University, working on moral and political philosophy.

Ketan Ramakrishnan is a JD candidate at Yale Law School and a DPhil candidate in philosophy at the University of Oxford.

Introduction, Jeff McMahan
1 Personal Identity, Prudence, and Ethics
1. Special Concern and Personal Identity, David O. Brink
2. Separating Persons, James Goodrich
3. Personal Identity and Impersonal Ethics, Tim Campbell
4. Temporal Neutrality and the Bias toward the Future, Samuel Scheffler
5. What is the Opposite of Well-Being?, Shelly Kagan
6. Parfit on Love and Partiality, Roger Crisp
2 Normative Ethical Theory
7. Individualist Utilitarianism and Converging Theories of Rights, Elizabeth Ashford
8. Parfit s Reorientation: From Revisionism to Conciliationism, Ingmar Persson
9. Parfit s Final Arguments in Normative Ethics, Brad Hooker
10. Parfit on Act Consequentialism, Katarzyna de Lazari-Radek and Peter Singer
11. Nonlegislative Justification: Against Legalist Moral Theory, Liam Murphy
3 Reasons
12. Doing Right by Wrong, Stephen Darwall
13. Giving Reasons and Given Reasons, John Broome
4 Moral Mathematics: Aggregation, Overdetermination, and Harm
14. Reply to Parfit's "Innumerate Ethics", John Taurek
15. Defence Against Parfit's Torturers, Jeff McMahan
16. Overdetermination and Obligation, Victor Tadros
17. What is Harming?, Molly Gardner
5 Egalitarianism and Prioritarianism
18. Prioritarianism, Risk, and the Gap Between Prudence and Morality, Nils Holtug
19. Relational Egalitarianism: Telic and Deontic, Kasper Lippert-Rasmussen
6 Supererogation
20. Duties That Become Supererogatory or Forbidden?, F. M. Kamm
21. More Supererogatory, Thomas Hurka and Evangeline Tsagarakis