Nondeterminacy and Population Ethics

This paper synthesizes a general view out of Derek Parfit’s last views on how to avoid the Repugnant Conclusion and presents the general features of a plausible theory of population ethics based on Parfit’s suggestions. The paper argues that a plausible population axiology provides only partial orderings and implies that some outcomes are nondeterminate in their ranking. The paper shows, first, how the combination of what Parfit calls “imprecise equality” and the “Wide Dual Person-Affecting Principle” allows one to avoid both the Continuum Argument and the Improved Mere Addition Paradox. Second, the paper shows how this is enough to in principle also refute Gustaf Arrhenius’s impossibility theorems. Third, the paper suggests that a plausible population axiology must allow for nondeterminacy, that whatever the substance of the axiology is, it can only provide partial orderings of outcomes, and that if we revise Arrhenius’s adequacy conditions these can condition what a satisfactory population axiology looks like. Finally, the paper illustrates how one can apply normative theories that allow for nondeterminacy and also infer formal constraints on the theories in light of the consequences of their application.

Population Ethics, the Mere Addition Paradox, and the Structure of Consequentialism

In this paper, I describe three structural issues population ethics raises for any form of consequentialism that embraces what we can call the basic maximizing idea, the idea that it makes things better, in a morally relevant sense, to make things better for people. What we say about those structural issues will in turn determine what we say about some of the most challenging problems of population ethics. I explore a handful of our options here, discarding some and leaving others on the table. My primary focus is on how those options propose to resolve the mere addition paradox, a population problem that is important in its own right and whose resolution is defining for what we will want to say about many other population problems.

Multidimensional Consequentialism and Population Ethics

The main claim of this chapter is that multidimensional consequentialists have reason to reject some of the key premises of Parfit’s Mere Addition Paradox as well as Arrhenius’s sixth impossibility theorem. The latter is the most general and far-reaching impossibility theorem in the literature on population ethics. The chapter shows that multidimensional consequentialists can reasonably maintain that the mere addition of people who have lives worth living is not always entirely right. To add what Parfit calls “extra people” is right with respect to one moral aspect (the size of the population) but wrong with respect to another (the average quality of life).

THE PARITY VIEW AND INTUITIONS OF NEUTRALITY

One response to Derek Parfit's ‘mere addition paradox’ invokes the relation of ‘parity’. Since parity is a form of ‘incommensurateness’ in John Broome's terms, three doubts which Broome raises about accounts involving incommensurateness in Weighing Lives pose a challenge for this response. I discuss two of these. They emerge from a discussion of various intuitions about ‘neutrality’. I argue that an account based on parity may be no less consistent with Broome's intuitions than is his own vagueness view.

Welfare and Outcome

In Inequality, Larry Temkin attacks ‘The Slogan’: ‘One Situation cannot be [morally] worse (or better) than another in any respect if there is no one for whom it is worse (or better) in any respect.’ Temkin notes that the Slogan has great intuitive appeal. It underlies, for example, the conviction that it is irrational to prefer a Pareto-inferior outcome; the transition from egalitarianism to the difference principle; Robert Nozick's Wilt Chamberlain example; defense of appropriation under the Lockean proviso; and Derek Parfit's Mere Addition Paradox. As an egalitarian, Temkin's main concern with the Slogan is the support it gives to the ‘leveling down objection’ to egalitarianism: the egalitarian finds it to be in some respect an improvement that the better-off are leveled down to the position of the worse-off, without any gain to the worse-off. The Slogan condemns this: leveling down cannot be better in any respect, since there is no one for whom it is better in any respect.