This book is a defense of modal realism; the thesis that our world is but one of a plurality of worlds, and that the individuals that inhabit our world are only a few out of all the inhabitants of all the worlds. Lewis argues that the philosophical utility of modal realism is a good reason for believing that it is true.

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)

According to impersonal moralities, welfare is good, period. Therefore, it is good that welfare is realised, whether by the benefiting of individuals who already exist or by the bringing of new...

This is about the rights and wrongs of bringing people into existence. In a nutshell: sometimes what matters is not what would have happened to you, but what would have happened to the person who would have been in your position, even if that person never actually exists.

Since the last ice age, when ice enveloped most of the northern continents, the earth has warmed by about five degrees. Within a century, it is likely to warm by another four or five. This revolution in our climate will have immense and mostly harmful effects on the lives of people not yet born. We are inflicting this harm on our descendants by dumping greenhouse gases into the atmosphere. We can mitigate the harm a little by taking measures to control (...) our emissions of these gases, and to adapt to the changes by, for instance, building sea walls around coastlines threatened by rising sea levels. But these measures will be very expensive, and the costs will be born by us, the present generation, whereas the benefits will come to future generations. How much should we sacrifice for the sake of the future? Economists and philosophers have independently worked on the question of our responsibility to future generations. This book brings their work together and applies it to global warming. It suggests a programme for future research on the economic and ethical issues. The book is intended for economists, and for philosophers and other social scientists who have a little knowledge of economic methods. (shrink)

Parfit's requirements for an ideal Theory X cannot be fully met since the Mere Addition Principle and Non-Antiegalitarianism imply the Repugnant Conclusion: Theory X does not exist. However, since the Repugnant Conclusion is really compelling, the Impersonal Total Principle should be adopted for impartial comparisons concerning future generations. Nevertheless, where our own interests are affected, we may yet choose to be partial, trading off our concern for future goodness with our self-interests. Theory X' meets all Parfit's requirements except the Mere (...) Addition Principle in less compelling cases. (shrink)

Parfit’s (1984) Non-Identity Problem provides a strong line of argument that we cannot be harmed by pre-conception choices or actions. I argue that we can no longer appeal to the Non-Identity problem in order to justify using pre-conception genetic screening and selection techniques as a harmless tool to determine the genetic constitution of future individuals. My criticism of the Non-Identity problem is based on a rejection of the metaphysical foundations of Parfit’s argument - Kripke’s (1980) essentialist arguments for the necessity (...) of origin. I offer an alternative account of modal harms based on counterpart theory such as that offered by David Lewis (1986). On this account, individuals can make legitimate harm claims in regard to pre-conception choices made in determining their genetic constitution by appeal to their counterparts across possible worlds. (shrink)

Parfit’s (1984) Non-Identity Problem provides a strong line of argument that we cannot be harmed by pre-conception choices or actions. I argue that we can no longer appeal to the Non-Identity problem in order to justify using pre-conception genetic screening and selection techniques as a harmless tool to determine the genetic constitution of future individuals. My criticism of the Non-Identity problem is based on a rejection of the metaphysical foundations of Parfit’s argument - Kripke’s (1980) essentialist arguments for the necessity (...) of origin. I offer an alternative account of modal harms based on counterpart theory such as that offered by David Lewis (1986). On this account, individuals can make legitimate harm claims in regard to pre-conception choices made in determining their genetic constitution by appeal to their counterparts across possible worlds. (shrink)

Derek Parfit has famously pointed out that ‘total’ utilitarian views, such as classical hedonistic utilitarianism, lead to the conclusion that, to each population of quite happy persons there corresponds a more extensive population with people living lives just worth living, which is better. In particular, for any possible population of at least ten billion people, all with a very high quality of life, there must be some much larger imaginable population whose existence, if other things are equal, would be better, (...) even though its members have lives that are barely worth living. This world is better if the sum total of well-being is great enough, and it is great enough if only enough sentient beings inhabit it. This conclusion has been considered by Parfit and others to be ‘repugnant’. (shrink)

This article critically examines some of the inconsistency objections that have been put forward by John Broome, Larry Temkin and others against the so-called "person-affecting," or "person-based," restriction in normative ethics, including "extra people" problems and a version of the nonidentity problem from Kavka and Parfit. Certain Pareto principles and a version of the "mere addition paradox" are discussed along the way. The inconsistencies at issue can be avoided, it is argued, by situating the person-affecting intuition within a non-additive form (...) of maximizing consequentialism – a theory which then competes with such additive, or aggregative, forms of maximizing consequentialism as "totalism" and "averagism.". (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Ethics & the Enviornment 6.2 (2001) 114-118 [Access article in PDF] Book Review Child versus Childmaker: Future Persons and Present Duties in Ethics and the Law Child versus Childmaker: Future Persons and Present Duties in Ethics and the Law. Melinda A. Roberts. Lanham, Md.: Rowman & Littlefield, 1998. Pp. 235. ISBN 0-8476-8901-8 (Paperback) This book will provide the reader with a systematic examination of some of the most difficult (...) philosophical issues involved in procreation, and most notably those raised by wrongful life claims and the non-identity problem. Can an action without which a given child would not even exist be simultaneously said to harm this very child? This is the key question addressed in this book. It is relevant not only to bioethicists, but also to those concerned with the possibility of harming members of future generations in general. The author proceeds with remarkable clarity in three steps. First, she unveils the core intuition and unfolds the key implications of what is standardly referred to as the person-affecting view. Second, she focuses on the now famous non-identity problem that is supposed to raise a serious challenge to the plausibility of the person-affecting view. Third, wrongful life and human cloning are taken as illustrations of the problem.The starting point is thus the person-affecting or personalist view. The author argues that what is at stake in such a view is not only a concern for [End Page 114] persons (as opposed to plants or stones), but also for definite persons. The core intuition that "what is bad must be bad for someone" (Derek Parfit) implies a comparison between two states of the same person. As she puts it, "the pairwise comparisons of worlds appealed to within personalism are always in respect of particular people" (6). This does not necessarily imply consequentialism, contrary to what Roberts claims (e.g., 1), at least if we understand the latter, for example, as Philip Pettit does. 1 Moreover, one may very well argue that what is at the heart of the person-affecting intuition is a sense that an action needs to be assessed on the basis of its effect on persons, which would not necessarily imply that such effects require a comparison between two states of the same person. Nevertheless, the extent to which a person-affecting conception--as defined by Roberts--will be in trouble depends on the extent to which comparisons between the same person's states cannot operate. This is precisely where to introduce the idea of a non-identity context, that is, a situation in which not committing an allegedly harmful act would or could also have meant the nonexistence of the allegedly harmed person. For example, had a medical doctor not committed this preconceptional diagnostic mistake (or a father taken a slower or faster means of transportation to come back home), this child would or could not have existed. Can we thus say that the practitioner harmed the child who turned out to be heavily handicapped due, for example, to a genetically transmissible disease (or that the father harmed his child by leaving him with a very polluted environment due to his use of big cars as a means of transportation)?One key feature of Roberts's approach is that she restricts the scope of the non-identity problem to cases where not committing the allegedly harmful action would have made it impossible for this child to have existed ("two-alternative" cases) (26, 319, 325). This entails that whenever this very child could still have come to existence in the allegedly harmful action's absence, whatever the likelihood of such a coming to existence, we would fall outside a non-identity context ("three-alternative" cases) (27; 94-95). What matters to Roberts is whether or not the same child could have been born better than he is, not whether he would, as a matter of fact, have been born at all. The consequence is that in cases where the same child could have been born, say, unhandicapped, the author remains... (shrink)

ABSTRACT Broome and others have argued that it makes no sense, or at least that it cannot be true, to say that it is better for a given person that he or she exist than not. That argument can be understood to suggest that, likewise, it makes no sense, or at least that it cannot be true, to say that it is worse for a given person that he or she exist than that he or she never have existed at (...) all. This argument is of critical importance to the question of whether consequentialist theory should take a traditional, aggregative form or a less conventional, person‐affecting, or person‐based, form. I believe that, potentially, the argument represents a far more serious threat to the person‐based approach than does, for example, Parfit's two medical programmes example. Parfit's example nicely illustrates the distinction between aggregative and person‐based approaches and raises important questions. But the example — though not, I think, by Parfit — is sometimes pressed into service as a full‐fledged counterexample against the person‐based approach. As such, I argue, the example is not persuasive. In contrast, the Broomeian argument, if correct, is definitive. For that argument relies on certain metaphysical assumptions and various uncontroversial normative claims — and hence nicely avoids putting into play the controversial normative claims that lie at the very heart of the debate. The purpose of the present paper, then, is to evaluate the Broomeian argument. I argue that this potentially definitive challenge to a person‐based approach does not in fact succeed. (shrink)

Ethicists and economists commonly assume that if A is all things considered better than B, and B is all things considered better than C, then A is all things considered better than C. Call this principle Transitivity. Although it has great conceptual, intuitive, and empirical appeal, I argue against it. Larry S. Temkin explains how three types of ethical principle, which cannot be dismissed a priori, threaten Transitivity: (a) principles implying that in some cases different factors are relevant to comparing (...) A to C than to comparing A to B or B to C; (b) principles of limited scope; (c) principles implying that morally relevant differences in degree can amount to differences in kind. My counterexamples employ a principle of type (c): pleasures and pains enormously different in intensity differ in kind. Temkin has also endorsed this type of counterexample, using arguments based on earlier drafts of this paper. (shrink)

This intuition may be contrasted with the incompatible intuitions that might support, say, average utilitarianism. According to average utilitarianism we should bring about that outcome which has the highest average utility. That someone would have a higher than average level of utility is, therefore, ceteris paribus a reason to act so that that person exists. Because of this, the basic intuition is a reason for rejecting average utilitarianism.

I defend the 'Repugnant' Conclusion that for any possible population of happy people, a population containing a sufficient number of people with lives barely worth living would be better. Four lines of argument converge on this conclusion, and the conclusion has a simple, natural theoretical explanation. The opposition to the Repugnant Conclusion rests on a bare appeal to intuition. This intuition is open to charges of being influenced by multiple distorting factors. Several theories of population ethics have been devised to (...) avoid the Repugnant Conclusion, but each generates even more counterintuitive consequences. The intuition opposing the Repugnant Conclusion is thus among the best candidates for an intuition that should be revised. (shrink)

1. Introduction. In a famous passage near the beginning of A Theory of Justice, John Rawls discusses utilitarianism’s notorious difficulties with justice. According to classic forms of utilitarianism, a certain course of action is morally right if it produces the greatest sum of satisfactions. And, as Rawls points out, the perplexing implication is “…that it does not matter, except indirectly, how this sum of satisfactions is distributed among individuals any more than it matters, except indirectly, how one man distributes his (...) satisfactions over time.” He concludes the passage by saying that “[u]tilitarianism does not take seriously the distinction between persons.”. (shrink)

Traditional ethical theories have paradoxical implications in regards to questions concerning procreation and our moral duties to future people. It has been suggested that the crux of the problem resides in an all too ‘impersonal’ axiology and that the problems of population axiology can be solved by adopting a ‘Person Affecting Restriction’ which in its slogan form states that an outcome can only be better than another if it is better for people. This move has been especially popular in the (...) context of medical ethics where many of the problems of population axiology are actualized. Examples are embryo or egg selection, pre-implantation genetic testing, assisted reproduction programmes, abortion, just to mention a few. I discuss a number of different interpretations of the Restriction and in particular one interpretation which I call Comparativism. According to this view, we should draw a distinction between uniquely and non-uniquely realizable people. The former people only exist in one out of two possible outcomes, whereas the latter exist in both of the compared outcomes. The idea is that we should give more weight to the well-being of non-uniquely realizable people or take it into account in a different way as compared to the well-being of uniquely realizable people. I argue that the different versions of the Person Affecting Restriction and Comparativism either have counterintuitive implications of their own or are compatible with traditional theories such as Utilitarianism. (shrink)

A search is under way for a theory that can accommodate our intuitions in population axiology. The object of this search has proved elusive. This is not surprising since, as we shall see, any welfarist axiology that satisfies three reasonable conditions implies at least one of three counter-intuitive conclusions. I shall start by pointing out the failures in three recent attempts to construct an acceptable population axiology. I shall then present an impossibility theorem and conclude with a short discussion of (...) how it might be extended to pluralist axiologies, that is, axiologies that take more values than welfare into account. (shrink)

This reprint of a collection of essays on problems concerning future generations examines questions such as whether intrinsic value should be placed on the preservation of mankind, what are our obligations to posterity, and whether potential people have moral rights.

Child Versus Childmaker investigates a "person-affecting" approach to ethical choice. A form of consequentialism, this approach is intended to capture the idea that agents ought both do the most good that they can and respect each person as distinct from each other. Focusing on cases in which a conflict of interest arises between "childmakers"—parents, infertility specialists, embryologists, and others engaged in the task of bringing new people into existence—and the children they aim to create, the author considers what we today (...) owe those who will come into existence tomorrow. (shrink)

Many economic problems are also ethical problems: should we value economic equality? how much should we care about preserving the environment? how should medical resources be divided between saving life and enhancing life? This book examines some of the practical issues that lie between economics and ethics, and shows how utility theory can contribute to ethics. John Broome's work has, unusually, combined sophisticated economic and philosophical expertise, and Ethics Out of Economics brings together some of his most important essays, augmented (...) with an updated introduction. The first group of essays deals with the relation between preference and value, the second with various questions about the formal structure of good, and the concluding section with the value of life. This work is of interest and importance for both economists and philosophers, and shows powerfully how economic methods can contribute to moral philosophy. (shrink)

1. Introduction. In a famous passage near the beginning of A Theory of Justice, John Rawls discusses utilitarianism’s notorious difficulties with justice. According to classic forms of utilitarianism, a certain course of action is morally right if it produces the greatest sum of satisfactions. And, as Rawls points out, the perplexing implication is “…that it does not matter, except indirectly, how this sum of satisfactions is distributed among individuals any more than it matters, except indirectly, how one man distributes his (...) satisfactions over time.” He concludes the passage by saying that “[u]tilitarianism does not take seriously the distinction between persons.”. (shrink)

In Derek Parfit's original formulation the Repugnant Conclusion is characterized as follows: “For any possible population of at least ten billion people, all with a very high quality of life, there must be some much larger imaginable population whose existence, if other things are equal, would be better even though its members have lives that are barely worth living” (Parfit 1984). The Repugnant Conclusion highlights a problem in an area of ethics which has become known as population ethics . The (...) last three decades have witnessed an increasing philosophical interest in questions such as “Is it possible to make the world a better place by creating additional happy creatures?” and “Is there a moral obligation to have children?” The main problem has been to find an adequate theory about the moral value of states of affairs where the number of people, the quality of their lives, and their identities may vary. Since, arguably, any reasonable moral theory has to take these aspects of possible states of affairs into account when determining the normative status of actions, the study of population ethics is of general import for moral theory. As the name indicates, Parfit finds the Repugnant Conclusion unacceptable and many philosophers agree. However, it has been surprisingly difficult to find a theory that avoids the Repugnant Conclusion without implying other equally counterintuitive conclusions. Thus, the question as to how the Repugnant Conclusion should be dealt with and, more generally, what it shows about the nature of ethics has turned the conclusion into one of the cardinal challenges of modern ethics. (shrink)

As the title of this paper indicates, I’m going to discuss what we ought to do in situations where our actions affect future generations. More specifically, I shall focus on the moral problems raised by cases where our actions affect who’s going to live, their number and their well being. I’ll start, however, with population axiology. Most discussion in population ethics has concentrated on how to evaluate populations in regard to their goodness, that is, how to order populations by the (...) relations “is better than” and “is as good as”. This field has been riddled with “paradoxes” which purport to show that our considered beliefs are inconsistent in cases where the number of people and their welfare varies. Derek Parfit’s Mere Addition Paradox is a case in point. The main question of my paper concerns the implication of such axiological paradoxes for normative theories. Do the axiological paradoxes translate into paradoxes for normative theories or will they, as some believe, disappear if we switch to a normative framework? (shrink)

In "Futurc Generations: Further Problems,"‘ and Part Four of Reasons and Persons} Derek Pariit raises many perplexing questions. Although some think his ingenious arguments little more than delightful puzzles, I believe they challenge some of our deepest beliefs. In this article, I examine some of Pariit’s arguments, focusing mainly on "The Mere Addition Paradox." If my analysis is correct, Parfit’s arguments have extremely interesting and important implications that not even Pariit rcalized. In Part I, I present ParHt’s argument for the (...) Merc Addition Paradox, and show that given Pa.rHt’s assumptions, a radical conclusion seems t0 follow; the notion of "bctter th2m"—indced, even the notion of "aH things.. (shrink)