Challenging, with several powerful arguments, some of our deepest beliefs about rationality, morality, and personal identity, Parfit claims that we have a false view about our own nature. It is often rational to act against our own best interersts, he argues, and most of us have moral views that are self-defeating. We often act wrongly, although we know there will be no one with serious grounds for complaint, and when we consider future generations it is very hard to avoid conclusions (...) that most of us will find very disturbing. (shrink)

This is a major work in moral philosophy, the long-awaited follow-up to Parfit's 1984 classic Reasons and Persons, a landmark of twentieth-century philosophy. Parfit now presents a powerful new treatment of reasons and a critical examination of the most prominent systematic moral theories, leading to his own ground-breaking conclusion.

Derek Parfit presents the third volume of On What Matters, his landmark work of moral philosophy. Parfit develops further his influential treatment of reasons, normativity, the meaning of moral discourse, and the status of morality. He engages with his critics, and shows the way to resolution of their differences.

One of the central debates within contemporary Anglo-American political philosophy concerns how to formulate an egalitarian theory of distributive justice which gives coherent expression to egalitarian convictions and withstands the most powerful anti-egalitarian objections. This book brings together many of the key contributions to that debate by some of the world’s leading political philosophers: Richard Arneson, G.A. Cohen, Ronald Dworkin, Thomas Nagel, Derek Parfit, John Rawls, T.M. Scanlon, and Larry Temkin.

We can start with some science fiction. Here on Earth, I enter the Teletransporter. When I press some button, a machine destroys my body, while recording the exact states of all my cells. This information is sent by radio to Mars, where another machine makes, out of organic materials, a perfect copy of my body. The person who wakes up on Mars seems to remember living my life up to the moment when I pressed the button, and is in every (...) other way just like me. (shrink)

Suppose we discover how we could live for a thousand years, but in a way that made us unable to have children. Everyone chooses to live these long lives. After we all die, human history ends, since there would be no future people. Would that be bad? Would we have acted wrongly? Some pessimists would answer No. These people are saddened by the suffering in most people’s lives, and they believe it would be wrong to inflict such suffering on others (...) by having children. In earlier centuries, this bleak view was fairly plausible. But our successors would be able to prevent most human suffering. Some optimists would also answer No . . . These [views] are, I believe, deeply mistaken. Given what our successors could achieve in the next million or billion years, here and elsewhere in our galaxy, it would be likely to be very much worse if there were no future people. (shrink)

When we have a normative reason, and we act for that reason, it becomes our motivating reason. But we can have either kind of reason without having the other. Thus, if I jump into the canal, my motivating reason was provided by my belief; but I had no normative reason to jump. I merely thought I did. And, if I failed to notice that the canal was frozen, I had a reason not to jump that, because it was unknown to (...) me, did not motivate me. Though we can have normative reasons without being motivated, and vice versa, such reasons are closely related to our motivation. There are, however, very different views about what this relation is. This disagreement raises wider questions about what normative reasons are, and about which reasons there are. After sketching some of these views, I shall discuss some arguments by Williams, and then say where, in my opinion, the truth lies. [...] I [will] suggest why, as I believe, we should be non-reductive normative realists, and should regard all reasons as external. (shrink)

How many people should there be? Can there be overpopulation: too many people living? I shall present a puzzling argument about these questions, show how this argument can be strengthened, then sketch a possible reply.

According to the Repugnant Conclusion: Compared with the existence of many people who would all have some very high quality of life, there is some much larger number of people whose existence would be better, even though these people would all have lives that were barely worth living. I suggest some ways in which we might be able to avoid this conclusion. I try to defend a strong form of lexical superiority.

When Ingmar and I discuss metaphysics or morality, our views are seldom far apart. Hut on the subjects of this paper, rationality and reasons, we deeply disagree.

This article discusses the relation between prioritarian and egalitarian principles, whether and why we need to appeal to both kinds of principle, how prioritarians can answer various objections, especially those put forward by Michael Otsuka and Alex Voorhoeve, the moral difference between cases in which our acts could affect only one person or two or more people, veil of ignorance contractualism and utilitarianism, what prioritarians should claim about cases in which the effects of our acts are uncertain, the relative moral (...) importance of actual and expectable benefits, whether people should sometimes be given various chances of receiving benefits, and principles that appeal to competing claims. (shrink)

We can start with some science fiction. Here on Earth, I enter the Teletransporter. When I press some button, a machine destroys my body, while recording the exact states of all my cells. The information is sent by radio to Mars, where another machine makes, out of organic materials, a perfect copy of my body. The person who wakes up on Mars seems to remember living my life up to the moment when I pressed the button, and he is in (...) every other way just like me. Of those who have thought about such cases, some believe that it would be I who would wake up on Mars. They regard Teletransportation as merely the fastest way of travelling. Others believe that, if I chose to be Teletransported, I would be making a terrible mistake. On their view, the person who wakes up would be a mere Replica of me. (shrink)

sonable, in this sense, if we ignore, or give too little weight to, some other people's well-being or moral claims.' Some critics have suggested that, because Scanlon appeals to this sense of 'reasonable', his formula is empty. On this objection, whenever we believe that some act is wrong, we shall believe that people have moral claims not to be treated in this way. We could therefore argue that such acts are disallowed by some principle which no one could reasonably reject, (...) since anyone who rejected this principle would be giving too little weight to people's moral claims not to be treated in this way. Since everyone could claim that the principles which they accept could not be reasonably rejected, Scanlon's Formula would make no difference to our moral thinking. That is not so. If we reject the principles that disallow certain acts, we are denying that such acts are wrong. This denial would be unreasonable if it would give too little weight to some other people's moral claims. So Scanlon's Formula implies that.. (shrink)

How many people should there be? Can there be overpopulation: too many people living? I shall present a puzzling argument about these questions, show how this argument can be strengthened, then sketch a possible reply.

This is the second volume of a major new work in moral philosophy. It starts with critiques of Derek Parfit's work by four eminent moral philosophers, and his responses. The largest part of the volume is a self-contained monograph on normativity. The final part comprises seven new essays on Kant, reasons, and why the universe exists.

Suppose that we can help either one person or many others. Is it a reason t0 help the many that We should thus be helping more people? John Taurek thinks not. We may learn from his arguments.

There are two main views about the nature of personal identity. I shall briehy describe these views, say without argument which I believe to be true, and then discuss the implications of this view for one of the main conceptions of rationality. This conception I shall call "C1assical Prudence." I shall argue that, on what I believe to be the true view about personal identity, Classical Prudence is indefensible.

"From the Proceedings of the British Academy, London, volume LXV (1979)" - title page. Series: Henrietta Hertz Trust annual philosophical lecture -- 1978 Other Titles: Proceedings of the British Academy. Vol.65: 1979.

When is a moral theory self-defeating? I suggest the following. There are certain things we ought to try to achieve. Call these our moral aims. Our moral theory would be self-defeating if we believed we ought to do what will cause our moral aims to be worse achieved. Is this ever true? If so, what does it show?

DEREK PARFIT is senior research fellow at All Souls College, Oxford. He regularly teaches there and is also afŠliated with New York University and Harvard. He was educated at Oxford and was a Harkness Fellow at Columbia and Harvard. He has been a visiting professor at Princeton, Temple, Rice, and the University of Colorado at Boulder, and is a fellow of the British Academy and of the American Academy of Arts and Sciences. He has made major contributions to our understanding (...) of personal identity, philosophy of the mind, and ethics, and he is thought to be one of the most important moral philosophers of the past century. His many academic articles include “Personal Identity” (1971), “Overpopulation and the Quality of Life” (1986), “The Unimportance of Identity” (1995), and “Equality and Priority” (1997). Rationality and Morality and Rediscovering Reasons are forthcoming from Oxford University Press. His book Reasons and Persons (1984) has been described by Alan Ryan of The Sunday Times as “something close to a work of genius.”. (shrink)

The reasoning in this anthology shows how hard it is to form acceptable theories in cases that involve different numbers of people. That's highly important. And it gives us ground for worry about our appeal to particular theories in the other two kinds of case: those which involve the same numbers, in the different outcomes, though these are not all the same people, and those which do involve all and only the same people. But there is still a clear distinction (...) between these three kinds of case. And there may be some hope of 'quarantining' the impossibility, and the resulting scepticism, to Different Number Choices. Her's a partial analogy, which may be worth mentioning. It's very difficult to formulate acceptable welfarist theories that could apply to cases that involve infinite quantities of such things as suffering and happiness. That's a worry, but it doesn't undermine our confidence in the theories that can handle cases with only finite quantities. (shrink)

Presents actual cases of brain bisection; how we might be able to divide and reunite our minds; what explains the unity of consciousness at any time; the imagined case of full division, in which each half of our brain would be successfully transplanted into the empty skull of another body; why neither of the resulting people would be us; why this would not matter, since our relation to each of these people contains what matters in the prudential sense, giving us (...) reasons to care about these people, which are like our reasons to care about our own future;and how it is hard to believe that personal identity, or our own continued existence, is not what matters. (shrink)