Population axiology is the study of the conditions under which one state of affairs is better than another, when the states of affairs in ques- tion may differ over the numbers and the identities of the persons who ever live. Extant theories include totalism, averagism, variable value theories, critical level theories, and “person-affecting” theories. Each of these the- ories is open to objections that are at least prima facie serious. A series of impossibility theorems shows that this is no coincidence: (...) it can be proved, for various sets of prima facie intuitively compelling desiderata, that no axiology can simultaneously satisfy all the desiderata on the list. One’s choice of population axiology appears to be a choice of which intuition one is least unwilling to give up. (shrink)

John Taurek argues that, in a choice between saving the many or the few, the numbers should not count. Some object that this view clashes with the transitivity of ‘better than’; others insist the clash can be avoided. I defend a middle ground: Taurek cannot have transitivity, but that doesn’t doom his view, given a suitable conception of value. I then formalize and explore two conceptions: one context-sensitive, one multidimensional.

Why should ‘better than’ be transitive? The leading answer in ethics is that values do not change with context. But this cannot be the entire source of transitivity, I argue, since transitivity can fail even if values never change, so long as they are complex, with multiple dimensions combined non-additively. I conclude by exploring a new hypothesis: that all alleged cases of nontransitive betterness, such as Parfit’s Repugnant Conclusion, can and should be modelled as the result of complexity, not context-relativity.

According to the Welfare Diffusion Objection, we should reject Prioritarianism because it implies the ‘desirability of welfare diffusion’: the claim that it can be better for there to be less total wellbeing spread thinly between a larger total number of people, rather than for there to be more total wellbeing, spread more generously between a smaller total number of people. I argue that while Prioritarianism does not directly imply the desirability of welfare diffusion, Prioritarians are nevertheless implicitly committed to certain (...) principles for comparing different-number populations which, together with the Prioritarian same-person axiology, imply the desirability of welfare diffusion. (shrink)

This thesis discusses the possibility of limited moral trade-offs between different people’s welfare. In chapter 2, I introduce the two central limited trade-off conditions. First, according to minimal infinite superiority, significantly benefiting one person matters more than slightly benefiting each of any number of better-off people. Second, according to minimal finite superiority, significantly benefiting many people matters more than slightly benefiting one person. I consider both axiological and deontic interpretations of these conditions. However, I explain why none of the simple (...) classic moral principles—the simple total and the maximin principles—satisfy both conditions. Furthermore, in chapter 3, I strengthen several proved impossibility results according to which no moral theory satisfies weak interpretations of these central trade-off conditions and several other seemingly plausible minimal conditions. I show that giving up structural axiological and deontic conditions is not a satisfactory solution to these paradoxes. In chapter 4, I discuss the modification of a background assumption of these impossibility results on the measurement of welfare. I show that, given a modification that allows for lexicographically ordered welfare components, a total principle can satisfy all the conditions of the impossibility results. However, I argue that such a modification is not entirely satisfactory because it does not apply in certain instances of the paradoxes. In chapter 5, I discuss a further weakening of minimal infinite superiority. However, I show that a suggested possibility result based on this modification is not valid and that further moral conditions, such as minimal finite superiority, need to be modified. Moreover, I argue that these modified conditions and the principle suggested in the possibility proof—a minimax complaint principle—do not capture the basic idea of the two central limited trade-off conditions sufficiently well. In chapter 6, I argue that other principles suggested for the task—the total claim principles—share the same fate as the simple total principles or the minimax complaint principle. In chapter 7, I propose new principles that take their structural roots from voting theory. I show that, in contrast to the other principles discussed, these principles give plausible verdicts where the other principles failed. Finally, in chapter 8, I consider possible objections levelled against this proposal, and I suggest solutions and avenues for future research. (shrink)

Many argue that absolutist moral theories -- those that prohibit particular kinds of actions or trade-offs under all circumstances -- cannot adequately account for the permissibility of risky actions. In this dissertation, I defend various versions of absolutism against this critique, using overlooked resources from formal decision theory. Against the prevailing view, I argue that almost all absolutist moral theories can give systematic and plausible verdicts about what to do in risky cases. In doing so, I show that critics have (...) overlooked: (1) the fact that absolutist theories -- and moral theories, more generally -- underdetermine their formal decision-theoretic representations; (2) that decision theories themselves can be generalised to better accommodate distinctively absolutist commitments. Overall, this dissertation demonstrates that we can navigate a risky world without compromising our moral commitments. (shrink)