Philosophical discussions of prioritarianism, the view that we ought to give priority to those who are worse off, have hitherto been almost exclusively focused on cases involving a fixed population. The aim of this paper is to extend the discussion of prioritarianism to encompass also variable populations. I argue that prioritarianism, in its simplest formulation, is not tenable in this area. However, I also propose several revised formulations that, so I argue, show more promise.

Recently, in his Rolf Schock Prize Lecture, Derek Parfit has suggested a novel way of avoiding the Repugnant Conclusion by introducing what he calls “imprecision” in value comparisons. He suggests that in a range of important cases, populations of different sizes are only imprecisely comparable. Parfit suggests that this feature of value comparisons opens up a way of avoiding the Repugnant Conclusion without implying other counterintuitive conclusions, and thus solves one of the major challenges in ethics. In this article, I (...) try to clarify Parfit’s proposal and evaluate whether it will help us with the paradoxes in population ethics. (shrink)

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)

First published in 2000. Routledge is an imprint of Taylor & Francis, an informa company.

The cofounder of the Effective Altruism movement presents a counterintuitive approach anyone can use to make a difference in the world. While studying philosophy at Oxford University and trying to work out how he could have the greatest impact, William MacAskill discovered that most of the time and money aimed at making the world a better place achieves little. Why? Because individuals rarely have enough information to make the best choices. Confronting this problem head-on, MacAskill developed the concept of effective (...) altruism, a scientific, data-driven approach to making a difference that operates by asking these five questions: How much will this action improve others' lives? Is this the most effective action I can take? How useful is my contribution, given what others are already doing? What will happen if I don't do it? What are the chances of success, and how good would success be? Applying these principles, he demonstrates that many of our assumptions about doing good are misguided: he argues that one can potentially save more lives by working on Wall Street than as a heart surgeon, that cancer charities are not the best use of money, and that buying sweatshop-produced goods is a form of ethical consumption. MacAskill challenges us to think differently but argues that if we set aside our biases and rely on evidence and careful reasoning, each of us can make a tremendous difference. (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)

A central strand in philosophical debate over the just distribution of resources attempts to juggle three competing imperatives: helping those who are worst off, helping those who will benefit the most, and then – beyond this – determining when to aggregate such ‘worst off’ and ‘benefit’ claims, and when instead to treat no such claim as greater than that which any individual by herself can exert. Yet as various philosophers have observed, ‘we have no satisfactory theoretical characterization’ as to how (...) to weigh each of the three imperatives against one another, we find it ‘difficult to state... precise or comprehensive conclusions’, and we do not yet have a ‘metric for integrating the three measures’. In what follows, I offer an approach to weighing the three criteria against one another that yields resolutions – in Hard Cases of the ‘saving one infant's life versus replacing ten elderly people's hips’ sort – that are cardinally definitive, intuitively satisfactory and theoretically justified. (shrink)

From the ethicist the_ New Yorker_ calls “the most influential living philosopher,” a new way of thinking about living ethically.

Effective altruists recommend that we give large sums to charity, but by far their more central message is that we give effectively, i.e., to whatever charities would do the most good per dollar donated. In this paper, I’ll assume that it’s not wrong not to give bigger, but will explore to what extent it may well nonetheless be wrong not to give better. The main claim I’ll argue for here is that in many cases it would be wrong of you (...) to give a sum of money to charities that do less good than others you could have given to instead, even if it would not have been wrong of you not to give the money to any charity at all. I assume that all the charities under discussion here do positive good overall, do not cause harm, do not infringe rights, etc. What makes my main claim here particularly interesting is that it is inconsistent with what appears to be a fairly common assumption in the ethics of giving, according to which if it is not wrong of you to keep some sum of money for yourself, then it is likewise not wrong of you to donate it to any particular charity you choose. Roughly: if it’s up to you whether to donate the money, it’s also up to you where to donate the money. I challenge this common assumption. (shrink)

Is there some large number of very mild hangnail pains, each experienced by a separate person, which would be worse than two years of excruciating torture, experienced by a single person? Many people have the intuition that the answer to this question is No. However, a host of philosophers have argued that, because we have no intuitive grasp of very large numbers, we should not trust such intuitions. I argue that there is decent intuitive support for the No answer, which (...) does not depend on our intuitively grasping or imagining very large numbers. (shrink)

Derek Parfit has argued that egalitarianism is exposed to a levelling down objection because it implies, implausibly, that a change, which consists only in the better-off sinking to the level of the worse-off, is in one respect better, though it is better for nobody. He claims that, in contrast, the prioritarian view that benefits to the worse-off have greater moral weight escapes this objection. This article contends, first, that prioritarianism is equally affected by the levelling down objection as is egalitarianism, (...) but that this objection lacks force. Secondly, prioritarianism is less plausible than egalitarianism because it implies that lowering the level of equality by diffusing a quantity of welfare equally over as many recipients as possible is for the better all things considered, and that the outcome of such welfare diffusion would still be better in one respect, even if the quantity of welfare was radically reduced. (shrink)

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.

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)

Effective altruism is a philosophy and a social movement that aims to revolutionise the way we do philanthropy. It encourages individuals to do as much good as possible, typically by contributing money to the best-performing aid and development organisations. Surprisingly, this approach has met with considerable resistance among activists and aid providers who argue that effective altruism is insensitive to justice insofar as it overlooks the value of equality, urgency and rights. They also hold that the movement suffers from methodological (...) bias, reaching mistaken conclusions about how best to act for that reason. Finally, concerns have been raised about the ability of effective altruism to achieve systemic change. This article weighs the force of each objection in turn, and looks at responses to the challenge they pose. (shrink)

Population axiology concerns 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 impossibility results which seem to show that our considered beliefs are inconsistent in cases where the number of people and their welfare varies.1 All of these results have one thing in common, however. They all involve an adequacy condition that rules out Derek Parfit’s Repugnant Conclusion: (...) The Repugnant Conclusion: For any perfectly equal population with very high positive welfare, there is a population with very low positive welfare which is better, other things being equal.2 1 The informal Mere Addition Paradox in Parfit (1984), pp. 419ff is the locus classicus. For an informal proof of a similar result with stronger assumptions, see Ng (1989), p. 240. A formal proof with slightly stronger assumptions than Ng’s can be found in Blackorby and Donaldson (1991). For theorems with much weaker assumptions, see my (1999), (2000b), and especially (2000a), (2001), and (2009). 2 See Parfit (1984), p. 388. My formulation is more general than Parfit’s apart from that he doesn’t demand that the people with very high welfare are equally well off. Expressions such as “a population with very high positive welfare”, “a population with very low positive welfare”, etc., are elliptical for the more cumbersome phrases “a population consisting only of lives with.. (shrink)