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)

It has been argued that Prioritarianism violates Risky Non-Antiegalitarianism, a condition stating roughly that an alternative is socially better than another if it both makes everyone better off in expectation and leads to more equality. I show that Risky Non-Antiegalitarianism is in fact compatible with Prioritarianism as ordinarily defined, but that it violates some other conditions that may be attractive to prioritarians. While I argue that the latter conditions are not core principles of Prioritarianism, the choice between these conditions and (...) Risky Non-Antiegalitarianism nonetheless constitutes an important intramural debate for prioritarians. (shrink)

Existential happiness is happiness that one has a basic life at all. Having a basic life, as I understand it, involves being the subject of experiences and being an agent in some minimal sense. As I argue, existential happiness is a fitting response to having a basic life. To make this argument, I look at two possible accounts of the fittingness of existential happiness: the value of a basic life and attachment to the constitutive elements of one’s life. I also (...) consider a few possible sources of existential happiness, including encounters with death, counterfactual thinking, and hedonically positive feelings of awe directed toward one’s own consciousness. (shrink)

On person-affecting views in population ethics, the moral import of a person’s welfare depends on that person’s temporal or modal status. These views typically imply that – all else equal – we’re never required to create extra people, or to act in ways that increase the probability of extra people coming into existence. -/- In this paper, I use Parfit-style fission cases to construct a dilemma for person-affecting views: either they forfeit their seeming-advantages and face fission analogues of the problems (...) faced by their rival impersonal views, or else they turn out to be not so person-affecting after all. In light of this dilemma, the attractions of person-affecting views largely evaporate. What remains are the problems unique to them. (shrink)

Totalism states that one population is better than another iff it has higher total welfare. One counterintuitive consequence is the Repugnant Conclusion (RC). Totalism also entails that a very large population of animals with lives barely worth living is better than a smaller population of happier humans. Furthermore, the strategies that have been used to avoid the troubling normative implications of the RC do not work in the animal case, so we may have reason to bring about such a population. (...) I introduce the notion of ‘Efficiency of Welfare Production’ – that animals of different species vary in the efficiency with which they convert resources into welfare. If we want to maximize total welfare, without any speciesist bias, we should identify which species is most efficient and try to maximize the population of that species. This has counterintuitive implications whether we accept hedonism or a more sophisticated theory of welfare. (shrink)

In this paper, I discuss two different metaethical challenges based on population ethical impossibility results. According to the anti-realist challenge, the results pose a serious threat to the existence of objective moral facts. According to the skeptical challenge, the results pose a serious threat to the reliability of our moral intuitions. My aim is to systematically explore and evaluate these challenges. In addition to clarifying the issues, I argue that population ethical impossibility results do not in fact support any anti-realist (...) or skeptical conclusions. (shrink)

This paper introduces the Monstrous Conclusion, according to which, for any population, there is a better population consisting of just one individual (the Monster). The Monstrous Conclusion is deeply counterintuitive. I defend a version of Prioritarianism as a particularly promising population axiology that does not imply the Monstrous Conclusion. According to this version of Prioritarianism, which I call Asymptotic Prioritarianism, there is diminishing marginal moral importance of individual welfare that can get close to, but never quite reach, some upper limit. (...) I argue that Asymptotic Prioritarianism faces a theoretical cost, that I call the Absolute Priority Principle. However, the Absolute Priority Principle is an extreme version of what I call the Trade-off Condition, an already noteworthy problem facing other (more widely endorsed) versions of Prioritarianism. I conclude that it is better for a theory to imply the Absolute Priority Principle and avoid the Monstrous Conclusion than to imply the Monstrous Conclusion and the Trade-off Condition. The potential for Asymptotic Prioritarianism is substantial. (shrink)

Many of us think human extinction would be a very bad thing, and that we have moral reasons to prevent it. But there is disagreement over what would make extinction so bad, and thus over what grounds these moral reasons. Recently, several theorists have argued that our reasons to prevent extinction stem not just from the value of the welfare of future lives, but also from certain additional values relating to the existence of humanity itself (for example, humanity’s “final” value, (...) or the value of humanity in itself). In this paper, I argue against these “additional value” views. Despite their initial appeal, these views will inevitably face conflicts between the additional values to which they appeal, and the value of the welfare of future lives. And, I argue, the views cannot plausibly resolve these conflicts. In contrast, these conflicts do not arise for a rival view, on which our reasons to prevent extinction stem just from the value of the welfare of future lives. I conclude that this gives us reason to prefer the latter view, despite the greater initial plausibility of additional value views. (shrink)

Non-Archimedean population axiologies – also known as lexical views – claim (i) that a sufficient number of lives at a very high positive welfare level would be better than any number of lives at a very low positive welfare level and/or (ii) that a sufficient number of lives at a very low negative welfare level would be worse than any number of lives at a very high negative welfare level. Such axiologies are popular because they can avoid the (Negative) Repugnant (...) Conclusion and satisfy the adequacy conditions given in the central impossibility result in population axiology due to Gustaf Arrhenius. I provide a novel argument against them which appeals to the way that good and bad lives can intuitively outweigh one another. (shrink)

Critical-set views avoid the Repugnant Conclusion by subtracting some constant from the welfare score of each life in a population. These views are thus sensitive to facts about biographical identity: identity between lives. In this paper, I argue that questions of biographical identity give us reason to reject critical-set views and embrace the total view. I end with a practical implication. If we shift our credences towards the total view, we should also shift our efforts towards ensuring that humanity survives (...) for the long term. (shrink)

This thesis is about the moral reasons we have to do less than best. It consists of six chapters. Part I of the thesis proposes, extends, and defends reasons to do less than best. In Chapter One (“The Conditional Obligation”) I outline and reject two recent arguments from Joe Horton and Theron Pummer for the claim that we have a conditional obligation to bring about the most good. In Chapter Two (“Agglomeration and Agent-Relative Costs”) I argue that agent-relative costs can (...) justify permissions to less than best in a far greater range of decisions contexts than we currently believe. In Chapter Three (“Risk and Aggregation”) I discuss how anti-aggregative moral theories deal with risk, whilst proposing an argument in favour of ex-post moral theories. -/- In Part II of the thesis, I discuss longtermism, presenting a series of reasons to believe we have both significant permissions and obligations to prioritise those in the short-term. In Chapter Four (“Listening to Future People”) I criticise a recent argument presented by Andreas Mogensen for the claim we cannot have obligations grounded in the wellbeing of future people. I then show that, even permitting the existence of obligations to future people, we still have significant reasons to resist longtermism on the grounds of partiality. In Chapter Five (“The Complaints of Future People”) I argue that scepticism about aggregation is inconsistent with an obligation, or indeed even a permission, to help far future people. In Chapter Six (“Leaving the Present Behind”) I explore the moral significance of “dooming”, whilst arguing that we have a pro tanto reason of fairness to prioritise aiding those currently in existence. (shrink)

I argue that many of the priority rankings that have been proposed by effective altruists seem to be in tension with apparently reasonable assumptions about the rational pursuit of our aims in the face of uncertainty. The particular issue on which I focus arises from recognition of the overwhelming importance and inscrutability of the indirect effects of our actions, conjoined with the plausibility of a permissive decision principle governing cases of deep uncertainty, known as the maximality rule. I conclude that (...) we lack a compelling decision theory that is consistent with a long-termist perspective and does not downplay the depth of our uncertainty while supporting orthodox effective altruist conclusions about cause prioritization. GPI Working Paper No. 2-2019. (shrink)

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)

This thesis consists of a series of papers in population ethics: a subfield of normative ethics concerned with the distinctive issues that arise in cases where our actions can affect the identities or number of people of who ever exist. Each paper can be read independently of the others. In Chapter 1, I present a dilemma for Archimedean views in population axiology: roughly, those views on which adding enough good lives to a population can make that population better than any (...) other. In Chapter 2, I extend Gustaf Arrhenius’s famous impossibility theorems in population axiology into the domain of choices under risk. My risky impossibility theorems dispense with the assumption that welfare levels are finitely fine-grained, and so tell against lexical views in population axiology. In Chapter 3, I present objections to critical-level and critical-range views in population axiology. I then sketch out what I call the ‘Imprecise Exchange Rates View’ and argue that it is an attractive alternative. In Chapter 4, I address critical-level and critical-range views again. This time, I note that they are vulnerable to objections from biographical identity: identity between lives. I suggest that these objections give us reason to reject critical-level and critical-range views and embrace the Total View. In Chapter 5, I argue that objections of the same form – objections from personal identity – tell against person-affecting views in population ethics. In Chapter 6, I draw out some counterintuitive implications of two recent complaints-based theories of the procreation asymmetry. (shrink)

Is well-being the kind of thing that can be summed across individuals? This paper takes a measurement-theoretic approach to answering this question. To make sense of adding well-being, we would need to identify some natural "concatenation" operation on the bearers of well-being that satisfies the axioms of extensive measurement and can therefore be represented by the arithmetic operation of addition. I explore various proposals along these lines, involving the concatenation of segments within lives over time, of entire lives led alongside (...) one another or in sequence, and of evaluatively basic propositions via conjunction. All of these proposals turn out to carry highly controversial commitments about the good. I do not claim that these commitments are unacceptable. But they suggest that we cannot simply take for granted, as many philosophers do, that there is any such thing as the sum of well-being. (shrink)

Contemporary population ethics is dominated by views that aggregate by summing, whether of well-being or of some construct based on well-being. In contrast, average well-being is generally considered axiologically irrelevant. To many of us, however, the number of future people does not seem important, as long as it is sufficient to enable rich and varied life experiences, and as long as the population continues throughout time. It therefore seems relatively plausible to aggregate future well-being by averaging. In particular, it seems (...) plausible to value high average well-being at any particular time, and to do so for all future times. I present a time-sensitive version of the Average View that underpins such axiological intuitions. I also address a series of issues and objections that confront such a view. (shrink)

We examine a general class of variable-value population principles. Our particular focus is on the extent to which such principles can avoid the repugnant and sadistic conclusions. We show that if a mild limit property is imposed, avoidance of the repugnant conclusion implies the sadistic conclusion. This result generalizes earlier observations by showing that they apply to a substantially larger class of principles. Our second theorem states that, under the limit property, the axiom of mere addition also conflicts with avoidance (...) of the repugnant conclusion. This result is a consequence of a similar observation that appears in the earlier literature. (shrink)

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.

This essay introduces a new type of measure of social welfare, where populations are evaluated by their resemblance to an optimum population, which is an (in principle) possible population with the highest degree of social welfare, relative to some circumstances. Here it is argued to be the largest possible population where everyone fares maximally well. The new measure is responsive to quality of welfare, equality of welfare, and the number of people. It satisfies dominance and negative monotonicity, and it avoids (...) both the repugnant conclusion and a reverse repugnant conclusion for comparisons relative to our future on earth. (shrink)

How ought you to evaluate your options if you're uncertain about what's fundamentally valuable? A prominent response is Expected Value Maximisation (EVM)—the view that under axiological uncertainty, an option is better than another if and only if it has the greater expected value across axiologies. But the expected value of an option depends on quantitative probability and value facts, and in particular on value comparisons across axiologies. We need to explain what it is for such facts to hold. Also, EVM (...) is by no means self-evident. We need an argument to defend that it’s true. This book introduces an axiomatic approach to answer these worries. It provides an explication of what EVM means by use of representation theorems: intertheoretic comparisons can be understood in terms of facts about which options are better than which, and mutatis mutandis for intratheoretic comparisons and axiological probabilities. And it provides a systematic argument to the effect that EVM is true: the theory can be vindicated through simple axioms. The result is a formally cogent and philosophically compelling extension of standard decision theory, and original take on the problem of axiological or normative uncertainty. (shrink)

In the face of an impossibility result, some assumption must be relaxed. The Mere Addition Paradox is an impossibility result in population ethics. Here, I explore substantially weakening the decision-theoretic assumptions involved. The central finding is that the Mere Addition Paradox persists even in the general framework of choice functions when we assume Path Independence as a minimal decision-theoretic constraint. Choice functions can be thought of either as generalizing the standard axiological assumption of a binary “betterness” relation, or as providing (...) a general framework for a normative (rather than axiological) theory of population ethics. Path Independence, a weaker assumption than typically (implicitly) made in population ethics, expresses the idea that, in making a choice from a set of alternatives, the order in which options are assessed or considered is ethically arbitrary and should not affect the final choice. Since the result establishes a conflict between the relevant ethical principles and even very weak decision-theoretic principles, we have more reason to doubt the ethical principles. (shrink)

Some philosophers think that life is worth living not merely because of the goods and the bads within it, but also because life itself is good. I explain how this idea can be formalized by associating each version of such of a view with a function from length of life to the value generated by life itself. Then I argue that every version of the view that life itself is good faces some version of the following dilemma: either (1) good (...) human lives are worse than very long lives wholly devoid of pleasure, desire-satisfaction, knowledge, or any other goods, or (2) very short lives containing nothing but suffering are worth living. Since neither result is plausible, we ought to reject the view that life itself is good. On the view I favor, any given life may be worth living because of the goods that it contains, but life itself is neutral. (shrink)

This volume collects selected papers delivered at the 15th Conference of the International Society for Utilitarian Studies, which was held at Karlsruhe Institute of Technology in July 2018. It includes papers dealing with the past, present, and future of utilitarianism – the theory that human happiness is the fundamental moral value – as well as on its applications to animal ethics, population ethics, and the future of humanity, among other topics.

The Repugnant Conclusion served an important purpose in catalyzing and inspiring the pioneering stage of population ethics research. We believe, however, that the Repugnant Conclusion now receives too much focus. Avoiding the Repugnant Conclusion should no longer be the central goal driving population ethics research, despite its importance to the fundamental accomplishments of the existing literature.

According to Critical-Level Views in population axiology, an extra life improves a population only if that life’s welfare exceeds some fixed ‘critical level.’ An extra life at the critical level leaves the new population equally good as the original. According to Critical-Range Views, an extra life improves a population only if that life’s welfare exceeds some fixed ‘critical range.’ An extra life within the critical range leaves the new population incommensurable with the original. -/- In this paper, I sharpen some (...) old objections to these views and offer some new ones. Critical-Level Views cannot avoid certain Repugnant and Sadistic Conclusions. Critical-Range Views imply that lives featuring no good or bad components whatsoever can nevertheless swallow up and neutralise goodness or badness. Both classes of view entail that certain small changes in welfare correspond to worryingly large differences in contributive value. -/- I then offer a view that retains much of the appeal of Critical-Level and Critical-Range Views while avoiding the above pitfalls. On the Imprecise Exchange Rates View, the quantity of some good required to outweigh a given unit of some bad is imprecise. This imprecision is the source of incommensurability between lives and populations. (shrink)

This thesis consists of several independent papers in population ethics. I begin in Chapter 1 by critiquing some well-known 'impossibility theorems', which purport to show there can be no intuitively satisfactory population axiology. I identify axiological vagueness as a promising way to escape or at least mitigate the effects of these theorems. In particular, in Chapter 2, I argue that certain of the impossibility theorems have little more dialectical force than sorites arguments do. From these negative arguments I move to (...) positive ones. In Chapter 3, I justify the use of a 'veil of ignorance', starting from three more basic normative principles. This leads to positive arguments for various kinds of utilitarianism - the best such arguments I know. But in general the implications of the veil depend on how one answers what I call 'the risky existential question': what is the value to an individual of a chance of non-existence? I chart out the main options, and raise some puzzles for non-comparativism, the view that life is incomparable to non-existence. Finally, in Chapter 4, I consider the consequences for population ethics of the idea that what is normatively relevant is not personal identity, but a degreed relation of psychological connectedness. In particular, I pursue a strategy based in population ethics for understanding the controversial 'time-relative interests' account of the badness of death. (shrink)

Many philosophers have thought that aggregates of small, broadly dispersed evils don’t pose the same sort of challenge to theism that horrendous evils like the Nazi Holocaust do. But there are interesting arguments that purport to show that large enough aggregates of small evils are morally and axiologically equivalent to horrendous evils. Herein lies an intriguing and overlooked strategy for defending theism. In short: small evils, or aggregates of such evils, don’t provide decisive evidence against theism; there’s no relevant difference (...) between horrendous evils and aggregates of small evils; hence horrendous evils must not provide decisive evidence against theism, either. (shrink)

Derek Parfit was one of the most important and influential moral philosophers of the late 20th and early 21st centuries. This Element offers a critical introduction to his wide-ranging ethical thought, focusing especially on his two most significant works, Reasons and Persons and On What Matters, and their contribution to the consequentialist moral tradition. Topics covered include: rationality and objectivity, distributive justice, self-defeating moral theories, Parfit's Triple Theory, personal identity, and population ethics.

For aggregative theories of moral value, it is a challenge to rank worlds that each contain infinitely many valuable events. And, although there are several existing proposals for doing so, few provide a cardinal measure of each world's value. This raises the even greater challenge of ranking lotteries over such worlds—without a cardinal value for each world, we cannot apply expected value theory. How then can we compare such lotteries? To date, we have just one method for doing so (proposed (...) separately by Arntzenius, Bostrom, and Meacham), which is to compare the prospects for value at each individual location, and to then represent and compare lotteries by their expected values at each of those locations. But, as I show here, this approach violates several key principles of decision theory and generates some implausible verdicts. I propose an alternative—one which delivers plausible rankings of lotteries, which is implied by a plausible collection of axioms, and which can be applied alongside almost any ranking of infinite worlds. (shrink)

Which is better: a guarantee of a modest amount of moral value, or a tiny probability of arbitrarily large value? To prefer the latter seems fanatical. But, as I argue, avoiding such fanaticism brings severe problems. To do so, we must decline intuitively attractive trade-offs; rank structurally identical pairs of lotteries inconsistently, or else admit absurd sensitivity to tiny probability differences; have rankings depend on remote, unaffected events ; and often neglect to rank lotteries as we already know we would (...) if we learned more. Compared to these implications, fanaticism is highly plausible. (shrink)

Is there any number of people you should save from paralysis rather than saving one person from death? Is there any number of people you should save from a migraine rather than saving one person from death? Many people answer “yes” and “no,” respectively. The aim of partially aggregative moral views is to capture and justify combinations of intuitions like these. In this article, I develop a risk-based reductio argument that shows that there can be no adequate partially aggregative view. (...) I then argue that the only plausible response to this reductio is to accept a fully aggregative view. (shrink)

The spectre of the repugnant conclusion and the search for a population axiology that avoids it has endured as a focus of population ethics. This is in part because the repugnant conclusion is often interpreted as a defining problem for totalism, while the implications of averagism and related views are taken to illustrate the theoretical cost of avoiding the repugnant conclusion. However, we show that this interpretation cannot be sustained unless one focuses only on a special case of the repugnant (...) conclusion: namely, the subset of instances of the repugnant conclusion where there is no portion of the population unaffected by the choice between population outcomes (as in Derek Parfit’s original illustration). To avoid an inappropriate focus on only this proper subset of instances of the repugnant conclusion, we formulate a general characterization of the repugnant conclusion. We then prove formally that all leading welfarist axiologies imply this conclusion, including averagism and Ng’s Theory X0 , including probabilistic and ‘very repugnant’ variants that involve the addition of negative lives. We then prove that the full range of axiologies considered by population ethics each imply an extended version of the repugnant conclusion, including axiologies that are incomplete, intransitive, rank-dependent, person-affecting, and/or pluralist. The upshot is that the repugnant conclusion does not ultimately tell against any approach to axiology, and the methodological requirement to avoid the repugnant conclusion should be dropped from population axiology. (shrink)

The topic of this thesis is axiological uncertainty – the question of how you should evaluate your options if you are uncertain about which axiology is true. As an answer, I defend Expected Value Maximisation (EVM), the view that one option is better than another if and only if it has the greater expected value across axiologies. More precisely, I explore the axiomatic foundations of this view. I employ results from state-dependent utility theory, extend them in various ways and interpret (...) them accordingly, and thus provide axiomatisations of EVM as a theory of axiological uncertainty. (shrink)

A foundational problem in population ethics is the “repugnant conclusion", introduced by Derek Parfit in Reasons and Persons. It holds that for any possible population of at least ten billion lives of very high positive welfare, there is some larger possible population of lives of very low positive welfare whose existence would be better, if other things are equal. I call this claim RC1. In this article, I argue that by carefully considering the nature and variety of possible lives of (...) very low positive welfare, and distinguishing RC1 from a related but stronger claim I call RC2, we can show that RC1 is more acceptable than it first appears. It has been claimed that perfectionism— that is, a special concern for the best things in life—is a reason to reject the repugnant conclusion. I argue that although perfectionism gives us a reason to reject RC2, it does not give us any reason to reject, and might in fact support, RC1. In his last two papers on the subject, Parfit develops a strategy for avoiding the repugnant conclusion that appeals in part to perfectionism. In the final part of this article, I argue that Parfit’s strategy can help us avoid RC2 but not RC1. If I am right that RC1 is more acceptable than RC2, this may not be an unwelcome result. (shrink)

Total views imply what Derek Parfit has called ‘the repugnant conclusion’. There are several strategies aimed at debunking the intuition that this implication is repugnant. In particular, it goes away when we consider the principle of unrestricted instantiation, according to which any instantiation of the repugnant conclusion must appear repugnant if we should be warranted in relying on it as evidence against total theories. However, there are instantiations of the conclusion where it doesn't seem to be at all repugnant. Hence (...) there is nothing repugnant about the repugnant conclusion as such. The faults with total views have nothing to do with large numbers or with the conclusion as such. It is possible, if you like, to correct these putative faults even if you adopt some total view (different from utilitarianism). (shrink)

Totalism is the view that one distribution of well-being is better than another just in case the one contains a greater sum of well-being than the other. Many philosophers, following Parfit, reject totalism on the grounds that it entails the repugnant conclusion: that, for any number of excellent lives, there is some number of lives that are barely worth living whose existence would be better. This paper develops a theory of welfare aggregation—the lexical-threshold view—that allows totalism to avoid the repugnant (...) conclusion, as well as its analogues involving suffering populations and the lengths of individual lives. The theory is grounded in some independently plausible views about the structure of well-being, identifies a new source of incommensurability in population ethics, and avoids some of the implausibly extreme consequences of other lexical views, without violating the intuitive separability of lives. (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)

Larry Temkin famously argues that what he calls spectrum arguments yield strong reason to reject Transitivity, according to which the ‘all-things-considered better than’ relation is transitive. Spectrum arguments do reveal that the conjunctions of independently plausible claims are inconsistent with Transitivity. But I argue that there is very strong independent reason to reject such conjunctions of claims, and thus that the fact that they are inconsistent with Transitivity does not yield strong reason to reject Transitivity.

Recently, Derek Parfit has offered a novel solution to the “Repugnant Conclusion” that compared with the existence of many people whose quality of life would be very high, there is some much larger number of people whose existence would be better but whose lives would be barely worth living. On this solution, qualitative differences between two populations will often entail that the populations are merely “imprecisely” comparable. According to Parfit, this fact allows us to avoid the Repugnant Conclusion without violating (...) the transitivity of better than. In this paper, I argue that Parfit’s view nevertheless implies two objectionable conclusions. The first is an alternative version of the Repugnant Conclusion that, Parfit suggests, may not be all that repugnant. The second is a revised version of the first that is nearly identical to the Repugnant Conclusion. I conclude that Parfit’s view offers no escape from repugnance. (shrink)

I present a new argument for the repugnant conclusion. The core of the argument is a risky, intrapersonal analogue of the mere addition paradox. The argument is important for three reasons. First, some solutions to Parfit’s original puzzle do not obviously generalize to the intrapersonal puzzle in a plausible way. Second, it raises independently important questions about how to make decisions under uncertainty for the sake of people whose existence might depend on what we do. And, third, it suggests various (...) difficulties for leading views about the value of a person’s life compared to her nonexistence. (shrink)

We know that Homo sapiens will not exist forever. Given this, how should our species end? What are the reasons, if any, to delay our extinction? In this paper, I show that the pre-eminent reasons which favour prolonging the existence of the species are partial: they will arise from the particular attachments and projects of the final few generations. While there may also be impartial reasons to prolong the species, these reasons are liable, with time, to reverse their valence: we (...) can be reasonably confident that they will ultimately recommend hastening the demise of the species. Consequently, it is likely that our descendants will eventually face a difficult -- possibly tragic -- conflict, between partial duties that recommend living on, and an impartial duty to extinguish the species. (shrink)

Values are incommensurable when they cannot be measured on a single cardinal scale. Many philosophers suggest that incommensurability can help us solve the problems of population ethics. I agree. But some philosophers claim that populations bear incommensurable values merely because they contain different numbers of people, perhaps within some range. I argue that mere differences in how many people exist, even within some range, do not suffice for incommensurability. I argue that the intuitive neutrality of creating happy people is better (...) captured by a version of average utilitarianism. But this view is problematic. So I suggest a version of total utilitarianism that avoids the repugnant conclusion by appealing to incommensurable dimensions of wellbeing. (shrink)

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)

Several philosophers have defended versions of Minimax Complaint, or MC. According to MC, other things equal, we should act in the way that minimises the strongest individual complaint. In this paper, I argue that MC must be rejected because it has implausible implications in certain cases involving risk. In these cases, we can apply MC either ex ante, by focusing on the complaints that could be made based on the prospects that an act gives to people, or ex post, by (...) focusing on the complaints that could be made based on the actual results that an act has for people. I argue that MC has implausible implications either way. I then defend a view on which, other things equal, we should act in the way that minimizes the sum of complaints. (shrink)

If it is within our power to provide a significantly better world for future generations at a comparatively small cost to ourselves, we have a strong moral reason to do so. One way of providing a significantly better world may involve replacing our species with something better. It is plausible that in the not‐too‐distant future, we will be able to create artificially intelligent creatures with whatever physical and psychological traits we choose. Granted this assumption, it is argued that we should (...) engineer our extinction so that our planet's resources can be devoted to making artificial creatures with better lives. (shrink)

My thesis demonstrates that, despite a number of impossibility results, a satisfactory and coherent theory of population ethics is possible. It achieves this by exposing and undermining certain key assumptions that relate to the nature of welfare and personal identity. I analyse a range of arguments against the possibility of producing a satisfactory population axiology that have been proposed by Derek Parfit, Larry Temkin, Tyler Cowen and Gustaf Arrhenius. I conclude that these results pose a real and significant challenge. However, (...) in the absence of further evidence I reject the conclusion that they imply that the value of populations is either not precise or not transitive. Instead, I expose some fundamental assumptions behind these results. One key assumption is that something can only make a life better or worse if it makes that life better or worse for the person living it, i.e. it raises or lowers the ‘welfare level’ of that life. Although intuitively highly plausible, this assumption ignores the possibility that perspectives other than that of the person living a life may be relevant for evaluating the components of that life and that these should be incorporated into our all things considered judgements. I argue that episodes within a person’s life that are strongly psychologically connected may have a special normative significance, particularly if these episodes involve such things as the enjoyment of ‘the best things in life’ or the experience of great suffering. We have reason to assign an all things considered value to such strongly psychologically connected phases of a person’s life, where this value is not exhausted by the contributions these make to the welfare level of that person’s life as a whole. It follows that our all things considered evaluations of populations are often underdetermined by information about the welfare levels of the lives they contain. However, in certain cases, most notably in that of ‘the Repugnant Conclusion’, there is nevertheless sufficient information provided by the welfare levels of persons’ lives to allow us to infer facts about these components that make an all things considered difference to these evaluations. I argue that a failure to acknowledge these facts is the cause of the aforementioned impossibility results and that once they are taken into account it is possible to produce a satisfactory theory of population ethics. (shrink)

This paper defends a novel account of how to determine the intrinsic value of possible worlds. Section 1 argues that a highly intuitive and widely accepted account leads to undesirable consequences. Section 2 takes the first of two steps towards a novel account by clarifying and defending a view about value-contribution that is based on some of W. D. Ross’ claims about the value of pleasure. Section 3 takes the second step by clarifying and defending a view about value-suppression that (...) is based on Ross’ claims about the interplay between prima-facie duties. Section 4 states and defends the account that I call Rossian Totalism. According to this account, the atoms of intrinsic value within a world only sometimes contribute their intrinsic value to the value of that world. (shrink)

It's been argued that better- than is non-transitive – that there are some value bearers for which better- than fails to generate an acyclic ordering. Michael Huemer has offered a powerful objection to this view, which he dubs ‘The Dominance Argument’. In what follows, I consider the extent to which there is a plausible response to be made on behalf of those who hold that better- than is non-transitive. I conclude that there is.

When and why is it right to kill? When and why is it wrong? Torbjörn Tännsjö examines three theories on the ethics of killing in this book: deontology, a libertarian moral rights theory, and utilitarianism. The implications of each theory are worked out for different kinds of killing: trolley-cases, murder, capital punishment, suicide, assisted death, abortion, killing in war, and the killing of animals. These implications are confronted with our intuitions in relation to them, and our moral intuitions are examined (...) in turn. Only those intuitions that survive an understanding of how we have come to hold them are seen as 'considered' intuitions. The idea is that the theory that can best explain the content of our considered intuitions gains inductive support from them. We must transcend our narrow cultural horizons and avoid certain cognitive mistakes in order to hold considered intuitions. In this volume, suitable for courses in ethics and applied ethics, Tännsjö argues that in the final analysis utilitarianism can best account for, and explain, our considered intuitions about all these kinds of killing. (shrink)