This article articulates and defends a dissolution of the so-called repugnant conclusion, which focuses on the notion of life worth living figuring both in Parfit's formulation of the repugnant conclusion and in most responses to such a conclusion. The proposed dissolution demonstrates that the notion of life worth living is plagued by multiple ambiguities and that these ambiguities, in turn, hamper meaningful debate about both the issue of whether the repugnant conclusion can be avoided and the issue of whether the (...) repugnant conclusion is actually repugnant. This result does not exclude that some modified versions of the repugnant conclusion may yield valuable insights about the value of populations and the tenability of different axiological/ethical theories. Still, if the proposed dissolution is correct, then the repugnant conclusion rests on an ill-defined notion and we lack the information required to assess the merits of the repugnant conclusion. (shrink)

Much of the work in moral philosophy and the political debate on abortion has focused on when in human development personhood begins. In this article, using a variant of Derek Parfit’s view on personal identity, I instead frame the question as one of victimhood. I argue for what I call the Victim Requirement for the wrongness of killing–killing is wrong only if there is an identifiable victim. An identifiable victim is, temporally speaking, in the midst of a chain of psychological (...) connections in the sense of “Relation R.” I go on to argue for a version of psychological identity which makes consciousness a necessary condition of rational self-interest and numerical identity across time. The implications for the abortion debate, based upon the best neurological evidence, are that abortion cannot be wrong before at least 22 weeks of pregnancy and perhaps significantly later. I then respond to alternatives to my Victim Requirement and argue that they either fail on their own merits or are deeply problematic. Finally, I discuss the role of autonomy and consent in a world where fetal consciousness develops much earlier. (shrink)

One prominent welfarist axiology, critical-level utilitarianism, says that individual lives must surpass a specified ‘critical level’ in order to make a positive contribution to the comparative status of a given population. In this article I develop a new dilemma for critical-level utilitarians. When comparatively evaluating populations composed of different species, critical-level utilitarians must decide whether the critical level is a universal threshold or whether the critical level is a species-relative threshold. I argue that both thresholds lead to a range of (...) axiological puzzles and objections as yet undiscussed within the literature, and therefore conclude that critical-level utilitarianism should not be taken as a morally plausible welfarist axiology. I show that certain competitive formulations of critical range utilitarianism are subject to the argument too, and that further attempts to relativise critical levels to a particular group or category of welfare bearer are unsustainable. (shrink)

Is the overall value of a world just the sum of values contributed by each value-bearing entity in that world? Additively separable axiologies (like total utilitarianism, prioritarianism, and critical level views) say 'yes', but non-additive axiologies (like average utilitarianism, rank-discounted utilitarianism, and variable value views) say 'no'. This distinction is practically important: additive axiologies support 'arguments from astronomical scale' which suggest (among other things) that it is overwhelmingly important for humanity to avoid premature extinction and ensure the existence of a (...) large future population, while non-additive axiologies need not. We show, however, that when there is a large enough 'background population' unaffected by our choices, a wide range of non-additive axiologies converge in their implications with some additive axiology -- for instance, average utilitarianism converges to critical-level utilitarianism and various egalitarian theories converge to prioritiarianism. We further argue that real-world background populations may be large enough to make these limit results practically significant. This means that arguments from astronomical scale, and other arguments in practical ethics that seem to presuppose additive separability, may be truth-preserving in practice whether or not we accept additive separability as a basic axiological principle. (shrink)

Most people are skeptical of the claim that the expectation that a person would have a life that would be well worth living provides a reason to cause that person to exist. In this essay I argue that to cause such a person to exist would be to confer a benefit of a noncomparative kind and that there is a moral reason to bestow benefits of this kind. But this conclusion raises many problems, among which is that it must be (...) determined how the benefits conferred on people by causing them to exist weigh against comparable benefits conferred on existing people. In particular, might the reason to cause people to exist ever outweigh the reason to save the lives of existing people? (shrink)

Parfit’s Repugnant Conclusion argues, against intuition, that for any world A, another world Z with higher population and minimal well-being is better. That intuition is incorrect because the argument has not considered resources that support well-being. Z must have many more resources supporting well-being than A does. Z is repugnant because it spreads those resources among too many people; another world with Z’s resources and fewer people, if available, would be far superior. But Z is still better than A; it (...) is worth accepting its very large population to get the resources needed to support their well-being. (shrink)

This paper introduces a novel approach to evaluating theories of the good. It proposes evaluating these theories on the basis of their compatibility with the most plausible ways of calculating overall intrinsic value of a world. The paper evaluates the plausibility of egalitarianism using this approach, arguing that egalitarianism runs afoul of the more plausible ways of calculating the overall intrinsic value of a world. Egalitarianism conflicts with the general motivation for totalism and critical-level totalism, which is that independent contributions (...) of each individual’s life should be counted separately. It conflicts with the most plausible version of averagism because only the highly implausible simultaneous life-segment version of egalitarianism can make sense of inequality being disvaluable at a time. Egalitarianism combined with a diminishing marginal value theory also fails because it holds that, other things equal, the world is a better place when we reduce inequality by adding many people whose lives go very badly but whose sheer numbers lessen inequality. The discussion moves the debate about egalitarianism forward by circumventing the oft-discussed, but intractable, debate concerning the leveling down objection. It also reveals a promising new approach to critiquing theories of the good. (shrink)

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.

Can it be better or worse for a person to exist than not to exist at all? This old and challenging existential question has been raised anew in contemporary moral philosophy, mainly for two reasons. First, traditional “impersonal” ethical theories, such as utilitarianism, have counterintuitive implications in population ethics, for example, the repugnant conclusion. Second, it has seemed evident to many that an outcome can be better than another only if it is better for someone, and that only moral theories (...) that are in this sense “person affecting” can be correct. The implications of this Person-Affecting Restriction will differ radically, however, depending on which answer one gives to the existential question. The negative answer, which we argue against, would make the restriction quite untenable. Hence, many of the problems regarding our moral duties to future generations turn around the issue at hand. (shrink)

Total utilitarianism implies Parfit's repugnant conclusion. For any world containing ten billion very happy people, there is a better world where a vast number of people have lives barely worth living. One common response is to claim that life in Parfit's Z is better than he suggests, and thus that his conclusion is not repugnant. This paper shows that this strategy cannot succeeed. Total utilitarianism also implies a reverse repugnant conclusion. For any world where ten billion people have lives of (...) excruciating agony, there is a worse world where a vast number of people have lives almost worth living. This reverse repugnant conclusion is at least as repugnant as Parfit's original. If we avoid the latter by raising the zero level, then the former becomes more repugnant. We cannot save total utilitarianism by tinkering with the zero level. (shrink)

The aim of this paper is to discuss the plausibility of a certain position in the philosophical literature within which the Repugnant Conclusion is treated, not as repugnant, but as an acceptable implication of the total welfare principle. I will confine myself to focus primarily on Törbjörn Tännsjö’s presentation. First, I reconstruct Tännsjö’s view concerning the repugnance of the RC in two arguments. The first argument is criticized for (a) addressing the wrong comparison, (b) relying on the controversial claim that (...) the privileged people in our actual world only have lives barely worth living and (c) that Tännsjö’s identification between Z-lives and privileged lives is restricted to certain versions of the notion ‘barely worth living’ – a restriction that weakens the force of the argument. The second argument is criticized because some of it premises entailed (b) and (d) for its implausible claim that non-imaginable outcomes cannot be compared. (shrink)

Intergenerational impartiality requires putting the welfare of future generations at par with that of our own. However, rational choice requires weighting all welfare values by the respective probabilities of realization. As the risk of non-survival of mankind is strictly positive for all time periods and as the probability of non-survival is cumulative, the probability weights operate like discount factors, though justified on a morally justifiable and completely different ground. Impartial intertemporal welfare maximization is acceptable, though the welfare of people in (...) the very far future has lower effects as the probabilities of their existence are also lower. However, the effective discount rate on future welfare values justified on this ground is likely to be less than 0.1 per annum. Such discounting does not compromise environmental protection and sustainability unduly. The finiteness of our universe implies that the sum of our expected welfare to infinity remains finite, solving the paradox of having to compare different infinite values in optimal growth/conservation theories. (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)

The valence of a life – that is, whether it is good, bad or neutral – is an important consideration in population ethics. This paper examines various definitions of valence. The main focus is ‘temporal’ definitions, which define valence in terms of the ‘shape’ of a life’s value over time. The paper argues that temporal definitions are viable only with a restricted domain, and therefore are incompatible with certain substantive theories of well-being. It also briefly considers some popular non-temporal definitions, (...) and raises some problems for these. (shrink)

Fred Feldman has proposed a desert-adjusted version of utilitarianism,, as a plausible population axiology. Among other things, he claims that justicism avoids Derek Parfit's. This paper explains the theory and tries to straighten out some of its ambiguities. Moreover, it is shown that it is not clear whether justicism avoids the repugnant conclusion and that it is has other counter-intuitive implications. It is concluded that justicism is not convincing as a population axiology.

Intergenerational impartiality requires putting the welfare of future generations at par with that of our own. However, rational choice requires weighting all welfare values by the respective probabilities of realization. As the risk of non-survival of mankind is strictly positive for all time periods and as the probability of non-survival is cumulative, the probability weights operate like discount factors, though justified on a morally justifiable and completely different ground. Impartial intertemporal welfare maximization is acceptable, though the welfare of people in (...) the very far future has lower effects as the probabilities of their existence are also lower. However, the effective discount rate on future welfare values (distinct from monetary values) justified on this ground is likely to be less than 0.1 per annum. Such discounting does not compromise environmental protection and sustainability unduly. The finiteness of our universe implies that the sum of our expected welfare to infinity remains finite, solving the paradox of having to compare different infinite values in optimal growth/conservation theories. (shrink)

Parfit (Theoria 82:110–127, 2016) responded to the Sequence Argument for the Repugnant Conclusion by introducing imprecise equality. However, Parfit’s notion of imprecise equality lacked structure. Hájek and Rabinowicz (2022) improved on Parfit’s proposal in this regard, by introducing a notion of degrees of incommensurability. Although Hájek and Rabinowicz’s proposal is a step forward, and may help solve many paradoxes, it can only avoid the Repugnant Conclusion at great cost. First, there is a sequential argument for the Repugnant Conclusion that uses (...) weaker and intuitively more compelling assumptions than the Sequence Argument, and which Hájek and Rabinowicz’s proposal only undermines, in a principled way, by allowing for implausible weight to be put on the disvalue of inequality. Second, if Hájek and Rabinowicz do put such implausible weight on the disvalue of inequality, then they will have to accept that a population A is not worse than another same sized population B even though everyone in B is better off than anyone in A. (shrink)

Jeff McMahan appeals to what he calls the “Time-relative Interest Account of the Wrongness of Killing ” to explain the wrongness of killing individuals who are conscious but not autonomous. On this account, the wrongness of such killing depends on the victim’s interest in his or her future, and this interest, in turn, depends on two things: the goods that would have accrued to the victim in the future; and the strength of the prudential relations obtaining between the victim at (...) the time of the killing and at the times these goods would have accrued to him or her. More precisely, when assessing this interest, future goods should be discounted to reflect reductions in the strength of such relations. Against McMahan’s account I argue that it relies on an implausible “actualist” view of the moral importance of interests according to which satisfactions of future interests only have moral significance if they are satisfactions of actual interests. More precisely, I aim to show that the Time-relative Interest Account does not have the implications for the morality of killing that McMahan takes it to have, and implies, implausibly, that certain interest satisfactions which seem to be morally significant are morally insignificant because they are not satisfactions of actual interests. (shrink)

In this paper I address the objection to sufficientarianism posed by Paula Casal and Richard Arneson, that it is hard to conceive of a sufficiency threshold such that distribution is highly important just below it, and not required at all just above it. In order to address this objection, I elaborate on the idea that sufficientarianism structurally can be seen to require two separate thresholds, which may or may not overlap. I then argue that a version of such a view (...) is plausible. Lastly, I distinguish this view from related proposals in the literature. (shrink)

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)

Según el largoplacismo, los efectos a largo plazo de nuestras acciones son un aspecto crucial de las mismas. Esto se debe a que el futuro, dada su extensión, presumiblemente contendrá a la mayor parte de los seres que alguna vez existan. Hay, sin embargo, distintas objeciones que cuestionan la viabilidad de la propuesta largoplacista, señalando que tendríamos razones para priorizar el corto plazo. Estas objeciones apuntan a problemas relacionados con la representación de individuos que todavía no existen, la situación de (...) las generaciones futuras o la incertidumbre acerca de lo que ocurrirá en el largo plazo. Este artículo examina dichas objeciones y argumenta que ninguna de ellas supone una razón decisiva para rechazar el largoplacismo. (shrink)

Is the overall value of a world just the sum of values contributed by each value-bearing entity in that world? Additively separable axiologies (like total utilitarianism, prioritarianism, and critical level views) say 'yes', but non-additive axiologies (like average utilitarianism, rank-discounted utilitarianism, and variable value views) say 'no'. This distinction appears to be practically important: among other things, additive axiologies generally assign great importance to large changes in population size, and therefore tend to strongly prioritize the long-term survival of humanity over (...) the interests of the present generation. Non-additive axiologies, on the other hand, need not assign great importance to large changes in population size. We show, however, that when there is a large enough `background population' unaffected by our choices, a wide range of non-additive axiologies converge in their implications with additive axiologies—for instance, average utilitarianism converges with critical-level utilitarianism and various egalitarian theories converge with prioritarianism. We further argue that real-world background populations may be large enough to make these limit results practically significant. This means that arguments from the scale of potential future populations for the astronomical importance of avoiding existential catastrophe, and other arguments in practical ethics that seem to presuppose additive separability, may succeed in practice whether or not we accept additive separability as a basic axiological principle. (shrink)

Population ethics is widely considered to be exceptionally important and exceptionally difficult. One key source of difficulty is the conflict between certain moral intuitions and analytical results identifying requirements for rational (in the sense of complete and transitive) social choice over possible populations. One prominent such intuition is the Asymmetry, which jointly proposes that the fact that a possible child’s quality of life would be bad is a normative reason not to create the child, but the fact that a child’s (...) quality of life would be good is not a reason to create the child. This paper reports a set of questionnaire experiments about the Asymmetry in the spirit of economists’ empirical social choice. Few survey respondents show support for the Asymmetry; instead respondents report that expectations of a good quality of life are relevant. Each experiment shows evidence (among at least some participants) of dual-process moral reasoning, in which cognitive reflection is statistically associated with reporting expected good quality of life to be normatively relevant. The paper discusses possible implications of these results for the economics of population-sensitive social welfare and for the conflict between moral mathematics and population intuition. (shrink)

Few moral arguments have been made against vegetarian diets. One exception is the “Logic of the Larder:” We do animals a favor by purchasing their meat, eggs, and milk, for if we did not purchase these products, fewer animals would exist. This argument fails because many farm animals have lives that are probably not worth living, while others prevent a significant number of wild animals from existing. Even if this were not so, the purchase of animal products uses resources that (...) could otherwise be used to bring a much greater number of animals into existence. (shrink)

This paper uses a formal analysis of the relation of ‘parity’ to make sense of a well-known solution to Parfit’s ‘mere addition paradox’. This solution is sometimes dismissed as a recourse to ‘incomparability’. In this analysis, however, the solution is consistent with comparability, as well as transitivity of ‘better than’. The analysis is related to Blackorby, Bossert and Donaldson’s ‘incomplete critical-level generalised utilitarianism’ (ICLGU). ICLGU is inspired by Parfit’s work and can be related to the analysis of parity, though the (...) distinctive ‘mark’ of parity suggests that the boundaries of a set of critical levels is not exact. One has to allow for vagueness to make an account based on parity plausible. These accounts are then contrasted with Broome’s view which also involves vagueness. (shrink)

On parity views of mere addition if someone is added to the world at a range of well-being levels – or ‘neutral range’ – leaving existing people unaffected, addition is on a par with the initial situation. Two distinct parity views – ‘rough equality’ and fittingattitudes views – defend the ‘intuition of neutrality’. The first can be interpreted or adjusted so that it can rebut John Broome’s objection that the neutral range is wide. The two views respond in distinct ways (...) to two of Broome’s other objections. Both views can, nonetheless, be plausibly defended against these objections. (shrink)

A principal aim of the branch of ethics called ‘population theory’ or ‘population ethics’ is to find a plausible welfarist axiology, capable of comparing total outcomes with respect to value. This has proved an exceedingly difficult task. In this paper I shall state and discuss two ‘trilemmas’, or choices between three unappealing alternatives, which the population ethicist must face. The first trilemma is not new. It originates with Derek Parfit's well-known ‘Mere Addition Paradox’, and was first explicitly stated by Yew-Kwang (...) Ng. I shall argue that one horn of this trilemma is less unattractive than Parfit and others have claimed. The second trilemma, which is a kind of mirror image of the first, appears hitherto to have gone unnoticed. Apart from attempting to resolve the two trilemmas, I shall suggest certain features which I believe a plausible welfarist axiology should possess. The details of this projected axiology will, however, be left open. (shrink)

There exists a derived negative right to procreative freedom, including a right to in vitro fertilisation (IVF) and to the exercise of selective techniques such as preimplantation genetic diagnosis. This is an extensive freedom, including not only the right to the exercise of a responsible parenthood, but also, in rare cases, to wrong decisions. It includes also a right for less than perfect parents to the use of IVF, and for IVF doctors to assist them, if they want and can (...) agree about the terms. (shrink)

The ethics of emerging forms of artificial intelligence has become a prolific subject in both academic and public spheres. A great deal of these concerns flow from the need to ensure that these technologies do not cause harm—physical, emotional or otherwise—to the human agents with which they will interact. In the literature, this challenge has been met with the creation of artificial moral agents: embodied or virtual forms of artificial intelligence whose decision procedures are constrained by explicit normative principles, requiring (...) the implementation of what is commonly called artificial morality into these agents. To date, the types of reasoning structures and principles which inform artificial morality have been of two kinds: first, an ethically maximal vision of artificial morality which relies on the strict implementation of traditional moral theories such as Kantian deontology or Utilitarianism, and second, a more minimalist vision which applies stochastic AI techniques to large data sets of human moral preferences so as to illicit or intuit general principles and preferences for the design of artificial morality. Taken individually, each approach is unable to fully answer the challenge of producing inoffensive behavior in artificial moral agents, most especially since both forms are unable to strike a balance between the ideal set of constraints which morality imposes on one hand, and the types of constraints public acceptability imposes, on the other. We provide an alternative approach to the design of artificial morality, the Ethical Valence Theory, whose purpose is to accommodate this balance, and apply this approach to the case of autonomous vehicles. (shrink)