Does Climate Change Policy Depend Importantly on Population Ethics? Deflationary Responses to the Challenges of Population Ethics for Public Policy

Choosing a policy response to climate change seems to demand a population axiology. A formal literature involving impossibility theorems has demonstrated that all possible approaches to population axiology have one or more seemingly counterintuitive implications. This leads to the worry that because axiology is so theoretically unresolved as to permit a wide range of reasonable disagreement, our ignorance implies serious practical ignorance about what climate policies to pursue. We offer two deflationary responses to this worry. First, it may be that given the actual facts of climate change, all axiologies agree on a particular policy response. In this case, there would be a clear dominance conclusion, and the puzzles of axiology would be practically irrelevant (albeit still theoretically challenging). Second, despite the impossibility results, we prove the possibility of axiologies that satisfy bounded versions of all of the desiderata from the population axiology literature, which may be all that is needed for policy evaluation.

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.

J. S. Mill on Higher Pleasures and Modes of Existence

The passage of Mill’s Utilitarianism that sets out the condition in which one pleasure has a superior quality than another stokes interpretive controversy. According to the Lexical Interpretation, Mill takes one pleasure, P1 , to be of a superior quality than another, P2 , if, and only if, the smallest quantity of P1 is more valuable than any finite quantity of P2 . This paper argues that, while the Lexical Interpretation may be supported with supplementary evidence, the passage itself does not rule out qualitative superiority without lexical dominance, as it only requires P1 to be more valuable than any quantity of P2 that it is possible for someone to experience. Some will object that this concession to opponents of the Lexical Interpretation still renders Mill’s condition for qualitative superiority too demanding to be plausible. However, if Mill’s qualitative rankings apply to higher-order pleasures taken in modes of existence as such rather than to the pleasures of different activities chosen from within these modes, the objection loses much of its force. One upshot is that Mill may have more to contribute to debates in contemporary population axiology than is usually acknowledged.

A dilemma for lexical and Archimedean views in population axiology

Lexical views in population axiology can avoid the Repugnant Conclusion without violating Transitivity or Separability. However, they imply a dilemma: either some good life is better than any number of slightly worse lives, or else the ‘at least as good as’ relation on populations is radically incomplete. In this paper, I argue that Archimedean views face an analogous dilemma. I thus conclude that the lexical dilemma gives us little reason to prefer Archimedean views. Even if we give up on lexicality, problems of the same kind remain.

The impossibility of a satisfactory population prospect axiology (independently of Finite Fine-Grainedness)

Arrhenius’s impossibility theorems purport to demonstrate that no population axiology can satisfy each of a small number of intuitively compelling adequacy conditions. However, it has recently been pointed out that each theorem depends on a dubious assumption: Finite Fine-Grainedness. This assumption states that there exists a finite sequence of slight welfare differences between any two welfare levels. Denying Finite Fine-Grainedness makes room for a lexical population axiology which satisfies all of the compelling adequacy conditions in each theorem. Therefore, Arrhenius’s theorems fail to prove that there is no satisfactory population axiology. In this paper, I argue that Arrhenius’s theorems can be repurposed. Since all of our population-affecting actions have a non-zero probability of bringing about more than one distinct population, it is population prospect axiologies that are of practical relevance, and amended versions of Arrhenius’s theorems demonstrate that there is no satisfactory population prospect axiology. These impossibility theorems do not depend on Finite Fine-Grainedness, so lexical views do not escape them.

Does Climate Change Policy Depend Importantly on Population Ethics?

Choosing a policy response to climate change seems to demand a population axiology. A formal literature involving impossibility theorems has demonstrated that all possible approaches to population axiology have one or more seemingly counterintuitive implications. This leads to the worry that because axiological theory is radically unresolved, this theoretical ignorance implies serious practical ignorance about what climate policies to pursue. This chapter offers two deflationary responses to this worry. First, it may be that given the actual facts of climate change, all axiologies agree on a particular policy response. In this case, there would be a clear dominance conclusion, and the puzzles of axiology would be practically irrelevant (albeit still theoretically challenging). Second, despite the impossibility results, the authors prove the possibility of axiologies that satisfy bounded versions of all of the desiderata from the population axiology literature, which may be all that is needed for policy evaluation.

Population axiology and the possibility of a fourth category of absolute value

Critical-Range Utilitarianism is a variant of Total Utilitarianism which can avoid both the Repugnant Conclusion and the Sadistic Conclusion in population ethics. Yet Standard Critical-Range Utilitarianism entails the Weak Sadistic Conclusion, that is, it entails that each population consisting of lives at a bad well-being level is not worse than some population consisting of lives at a good well-being level. In this paper, I defend a version of Critical-Range Utilitarianism which does not entail the Weak Sadistic Conclusion. This is made possible by what I call ‘undistinguishedness’, a fourth category of absolute value in addition to goodness, badness, and neutrality.

Attachment and Axiology

Many discussions of future generations attempt to identify a satisfactory population axiology: a principle that would enable us to assess the relative value of total states of affairs that differ in population-related respects. Such an axiology would in turn supply the basis for a principle of beneficence, which would spell out our responsibilities for promoting optimal population outcomes. By contrast, the approach defended in this book is predominantly attachment-based. The reasons for caring about the fate of future generations discussed in previous chapters all depend on our existing values and evaluative attachments and on our conservative disposition to preserve and sustain the things that we value. This chapter appeals to the nature of valuing to clarify these forms of dependence, and it explores the contrast between the axiological and attachment-based approaches.