The notion of existential catastrophe is increasingly appealed to in discussion of risk management around emerging technologies, but it is not completely clear what this notion amounts to. Here, I provide an opinionated survey of the space of plausibly useful definitions of existential catastrophe. Inter alia, I discuss: whether to define existential catastrophe in ex post or ex ante terms, whether an ex ante definition should be in terms of loss of expected value or loss of potential, and what kind (...) of probabilities should be involved in any appeal to expected value. (shrink)

Longtermism is the thesis that in a large class of decision situations, the best thing we can do is what is best for the long-term future. The scope question for longtermism asks: how large is the class of decision situations for which this is true? In this paper, I suggest that the scope of longtermism may be narrower than many longtermists suppose. I identify a restricted version of longtermism: swamping axiological strong longtermism (swamping ASL). I identify three scope-limiting factors - (...) probabilistic and decision-theoretic phenomena which, when present, tend to reduce the prospects for swamping ASL. I argue that these scope-limiting factors are often present in human decision problems, then use two case studies from recent discussions of longtermism to show how the scope-limiting factors lead to a restricted, if perhaps nonempty, scope for swamping ASL. (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)

Longtermists have recently argued that it is overwhelmingly important to do what we can to mitigate existential risks to humanity. I consider three mistakes that are often made in calculating the value of existential risk mitigation. I show how correcting these mistakes pushes the value of existential risk mitigation substantially below leading estimates, potentially low enough to threaten the normative case for existential risk mitigation. I use this discussion to draw four positive lessons for the study of existential risk. -/- (...) . (shrink)

Longtermists claim that what we ought to do is mainly determined by how our actions might affect the very long-run future. A natural objection to longtermism is that these effects may be nearly impossible to predict — perhaps so close to impossible that, despite the astronomical importance of the far future, the expected value of our present actions is mainly determined by near-term considerations. This paper aims to precisify and evaluate one version of this epistemic objection to longtermism. To that (...) end, I develop two simple models for comparing ‘longtermist’ and ‘neartermist’ interventions, incorporating the idea that it is harder to make a predictable difference to the further future. These models yield mixed conclusions: if we simply aim to maximize expected value, and don’t mind premising our choices on minuscule probabilities of astronomical payoffs, the case for longtermism looks robust. But on some prima facie plausible empirical worldviews, the expectational superiority of longtermist interventions depends heavily on these ‘Pascalian’ probabilities. So the case for longtermism may depend either on plausible but non-obvious empirical claims or on a tolerance for Pascalian fanaticism. (shrink)

Why, if at all, should we object to economic inequality? Some central arguments – the argument from decreasing marginal utility for example – invoke instrumental reasons and object to inequality because of its effects. Such instrumental arguments, however, often concern only the static effects of inequality and neglect its intertemporal conse- quences. In this article, we address this striking gap and investigate income inequality’s intertemporal consequences, including its potential effects on humanity’s (very) long-term future. Following recent arguments around future generations (...) and so-called longtermism, those effects might arguably matter more than inequality’s short-term con- sequences. We assess whether we have instrumental reason to reduce economic inequality based on its intertemporal effects in the short, medium, and the very long term. We find a good short and medium-term instrumental case for lower economic inequality. We then argue, somewhat speculatively, that we have instrumental reasons for inequality reduction from a longtermist perspective too, primarily because greater inequality could increase existential risk. We thus have instrumental reasons to reduce inequality, regardless of which time-horizon we take. We then argue that from most consequentialist perspectives, this pro tanto reason also gives us all-things-considered reason. And even across most non-consequentialist views in philosophy, this argument gives us either an all-things-considered or at least weighty pro tanto reason against inequality. (shrink)

We begin by showing that every theory of the value of uncertain prospects must have one of three unpalatable properties. _Reckless_ theories recommend giving up a sure thing, no matter how good, for an arbitrarily tiny chance of enormous gain; _timid_ theories permit passing up an arbitrarily large potential gain to prevent a tiny increase in risk; _non-transitive_ theories deny the principle that, if A is better than B and B is better than C, then A must be better than (...) C. Having set up this trilemma, we study its horns. Non-transitivity has been much discussed; we focus on drawing out the costs and benefits of recklessness and timidity when it comes to axiology, decision theory, and normative uncertainty. (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)

Ruth Chang and Joseph Raz have both drawn far-reaching consequences for agency from the phenomenon of incommensurability. After criticizing their arguments, I outline an alternative view: if incommensurability is vagueness, then there are no substantial implications for agency, except perhaps a limited form of naturalistic voluntarism if our reasons are provided by desires.

Social decisions are often made under great uncertainty – in situations where political principles, and even standard subjective expected utility, do not apply smoothly. In the first section, we argue that the core of this problem lies in decision theory itself – it is about how to act when we do not have an adequate representation of the context of the action and of its possible consequences. Thus, we distinguish two criteria to complement decision theory under ignorance – Laplace’s principle (...) of insufficient reason and Wald’s maximin criterion. After that, we apply this analysis to political philosophy, by contrasting Harsanyi’s and Rawls’s theories of justice, respectively based on Laplace’s principle of insufficient reason and Wald’s maximin rule – and we end up highlighting the virtues of Rawls’s principle on practical grounds (it is intuitively attractive because of its computational simplicity, so providing a salient point for convergence) – and connect this argument to our moral intuitions and social norms requiring prudence in the case of decisions made for the sake of others. (shrink)

ABSTRACT If the future is highly sensitive to the past, then many of our acts have long-term consequences whose significance well exceeds that of their foreseeable short-term consequences. According to an influential argument by James Lenman, we should think that the future is highly sensitive to acts that affect people’s identities. However, given the assumption that chancy events are ubiquitous, the effects that our acts have are likely to dissipate over a short span of time. The sets of possible futures (...) left open by alternative acts are typically very similar in the same way that large random samples drawn from the same population are typically very similar. (shrink)

Variable-Value axiologies avoid Parfit’s Repugnant Conclusion while satisfying some weak instances of the Mere Addition principle. We apply calibration methods to two leading members of the family of Variable-Value views conditional upon: first, a very weak instance of Mere Addition and, second, some plausible empirical assumptions about the size and welfare of the intertemporal world population. We find that such facts calibrate these two Variable-Value views to be nearly totalist, and therefore imply conclusions that should seem repugnant to anyone who (...) opposes Total Utilitarianism only due to the Repugnant Conclusion. (shrink)

Our universe is both chaotic and (most likely) infinite in space and time. But it is within this setting that we must make moral decisions. This presents problems. The first: due to our universe's chaotic nature, our actions often have long-lasting, unpredictable effects; and this means we typically cannot say which of two actions will turn out best in the long run. The second problem: due to the universe's infinite dimensions, and infinite population therein, we cannot compare outcomes by simply (...) adding up their total moral values - those totals will typically be infinite or undefined. Each of these problems poses a threat to aggregative moral theories. But, for each, we have solutions: a proposal from Greaves let us overcome the problem of chaos, and proposals from the infinite aggregation literature let us overcome the problem of infinite value. But a further problem emerges. If our universe is both chaotic and infinite, those solutions no longer work - outcomes that are infinite and differ by chaotic effects are incomparable, even by those proposals. In this paper, I show that we can overcome this further problem. But, to do so, we must accept some peculiar implications about how aggregation works. (shrink)

Rational agents are supposed to maximize expected utility. But what are the options from which they choose? I outline some constraints on an adequate representation of an agent’s options. The options should, for example, contain no information of which the agent is unsure. But they should be sufficiently rich to distinguish all available acts from one another. These demands often come into conflict, so that there seems to be no adequate representation of the options at all. After reviewing existing proposals (...) for how to construe decision-theoretic options and finding them all wanting, I suggest that our model of rational agents should include a special domain of ‘virtual’ option propositions to serve as formal objects of deliberation and choice. (shrink)

According to hedonistic act utilitarianism, an act is morally right if and only if, and because, it produces at least as much pleasure minus pain as any alternative act available to the agent. This dissertation gives a partial defense of utilitarianism against two types of objections: action guidance objections and intuitive objections. In Chapter 1, the main themes of the dissertation are introduced. The chapter also examines questions of how to understand utilitarianism, including (a) how to best formulate the moral (...) explanatory claim of the theory, (b) how to best interpret the phrase "pleasure minus pain," and (c) how the theory is related to act consequentialism. The first part (Chapters 2 and 3) deals with action guidance objections to utilitarianism. Chapter 2 defines two kinds of action guidance: doxastic and evidential guidance. It is argued that utilitarianism is evidentially but not doxastically guiding for us. Chapter 3 evaluates various action guidance objections to utilitarianism. These are the objections that utilitarianism, because it is not doxastically guiding, is a bad moral theory, fails to be a moral theory, is an uninteresting and unimportant moral theory, and is a false moral theory. The second part (Chapters 4, 5 and 6) deals with intuitive objections to utilitarianism. Chapter 4 presents three intuitive objections: Experience Machine, Transplant, and Utility Monster. Three defenses of utilitarianism are subsequently evaluated. Chapter 5 and 6 introduces two alternative defenses of utilitarianism against intuitive objections, both of which concern the role that imagination plays in thought experimentation. In Chapter 5, it is argued that we sometimes unknowingly carry out the wrong thought experiment when we direct intuitive objections against utilitarianism. In many such cases, we elicit moral intuitions that we believe give us reason to reject utilitarianism, but that in fact do not. In Chapter 6, it is argued that using the right kind of sensory imagination when we perform thought experiments will positively affect the epistemic trustworthiness of our moral intuitions. Moreover, it is suggested that doing so renders utilitarianism more plausible. In Chapter 7, the contents of the dissertation are summarized. (shrink)

Longtermists claim that what we ought to do is mainly determined by how our actions might affect the very long-run future. A natural objection to longtermism is that these effects may be nearly impossible to predict -- perhaps so close to impossible that, despite the astronomical importance of the far future, the expected value of our present actions is mainly determined by near-term considerations. This paper aims to precisify and evaluate one version of this epistemic objection to longtermism. To that (...) end, I develop two simple models for comparing "longtermist" and "neartermist" interventions, incorporating the idea that it is harder to make a predictable difference to the further future. These models yield mixed conclusions: if we simply aim to maximize expected value, and don't mind premising our choices on minuscule probabilities of astronomical payoffs, the case for longtermism looks robust. But on some prima facie plausible empirical worldviews, the expectational superiority of longtermist interventions depends heavily on these "Pascalian" probabilities. So the case for longtermism may depend either on plausible but non-obvious empirical claims or on a tolerance for Pascalian fanaticism. (shrink)

I explain why, from the perspective of knowledge-centric anti-luck epistemology, objective act consequentialist theories of ethics imply skepticism about the moral status of our prospective actions and also tend to be self-defeating, undermining the justification of consequentialist theories themselves. For according to knowledge-centric anti-luck epistemology there are modal anti-luck demands on both knowledge and justification, and it turns out that our beliefs about the moral status of our prospective actions are almost never able to satisfy these demands if objective act (...) consequentialism is true. This kind of applied moral skepticism introduces problematic limits on our ability to use objective act consequentialism’s explanatory power as evidence for its truth. This is, in part, a product of higher-order defeat as I explain in the final section. There is, however, a silver lining for objective act consequentialists. For there is at least one type of objective act consequentialism, prior existence consequentialism, that is poised to avoid at least some of the epistemic problems discussed in this paper. (shrink)

Effective altruism is purportedly ecumenical towards different moral views, charitable causes, and evidentiary methods. I argue that effective altruists’ criticisms of purportedly less effective charities are inconsistent with their commitment to ecumenicity. Individuals may justifiably support charities other than those recommended by effective altruism. If effective altruists take their commitment to ecumenicity seriously, they will have to revise their criticisms of many of these charities.

In this entry, we discuss both the definition of effective altruism and objections to effective altruism, so defined.

According to the principle of indifference, when a set of possibilities is evidentially symmetric for you – when your evidence no more supports any one of the possibilities over any other – you're required to distribute your credences uniformly among them. Despite its intuitive appeal, the principle of indifference is often thought to be unsustainable due to the problem of multiple partitions: Depending on how a set of possibilities is divided, it seems that sometimes, applying indifference reasoning can require you (...) to assign incompatible credences to equivalent possibilities. This paper defends the principle of indifference from the problem of multiple partitions by offering two guides for how to respond. The first is for permissivists about rationality, and is modeled on permissivists' arguments for the claim that a body of evidence sometimes does not uniquely determine a fully rational credence function. The second is for impermissivists about rationality, and is modeled on impermissivists' arguments for the claim that a body of evidence does always uniquely determine a fully rational credence function. What appears to be a decisive objection against the principle of indifference is in fact an instance of a general challenge taking different forms familiar to both permissivists and impermissivists. (shrink)

Journal of Social Philosophy, EarlyView.

Artificially intelligent systems will be used to make increasingly important decisions about us. Many of these decisions will have to be made without universal agreement about the relevant moral facts. For other kinds of disagreement, it is at least usually obvious what kind of solution is called for. What makes moral disagreement especially challenging is that there are three different ways of handling it. _Moral solutions_ apply a moral theory or related principles and largely ignore the details of the disagreement. (...) _Compromise solutions_ apply a method of finding a compromise and taking information about the disagreement as input. _Epistemic solutions_ apply an evidential rule that treats the details of the disagreement as evidence of moral truth. Proposals for all three kinds of solutions can be found in the AI ethics and value alignment literature, but little has been said to justify choosing one over the other. I argue that the choice is best framed in terms of _moral risk_. (shrink)

Many people hold the constraint against doing harm, the view that the reason against doing harm is stronger than the reason against merely allowing harm, everything else being equal. Mogensen and MacAskill (2021) have recently argued that when considering indirect long-term consequences of our everyday behavior, the constraint against doing harm faces a problem: it has the absurd implication that we should do as little as possible in our lives. In this paper, I explore the view that, for behavior that (...) does not increase anyone’s ex ante risk of suffering harm, the reason against doing harm is not stronger than the reason against merely allowing harm, everything else being equal. I argue that this view is plausible, show how it solves the paralysis problem, and defend it against objections. (shrink)

This article is about the role of factual uncertainty for moral decision-making as it concerns the ethics of machine decision-making. The view that is defended here is that factual uncertainties require a normative evaluation and that ethics of machine decision faces a triple-edged problem, which concerns what a machine ought to do, given its technical constraints, what decisional uncertainty is acceptable, and what trade-offs are acceptable to decrease the decisional uncertainty.

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 longtermist perspective and does not downplay the depth of our uncertainty, while also supporting orthodox effective altruist conclusions about cause prioritization. (shrink)

Lenman 's cluelessness objection against consequentialism states that we are almost entirely clueless to the actual consequences of our action. In ‘Cluelessness,’ Hilary Greaves distinguishes between ‘simple’ and ‘complex’ cases of cluelessness and argues that the principle of indifference applies to ‘simple’ cases, thereby rescuing the ‘simple’ cases from the cluelessness objection. In this discussion note, I argue that Greaves's distinction between ‘simple’ and ‘complex’ cases fails and cluelessness is more problematic than Greaves believes.

[Comment] Donald Trump’s executive order on energy limits the costs and benefits of carbon to domestic sources. The argument for this executive order is that carbon policies should not be singled out from other policies as globally inclusive. Two independent arguments are offered for adopting a global social cost of carbon. The first is based on reinforcing norms in the face of commons tragedies. The second is based on the limitations of consequentialist analyses. We can distinguish consequences for which probabilistic (...) indifference is appropriate. The mechanisms for global effects for carbon are well-understood, whereas most policy effects are primarily domestic. [Open access]. (shrink)

Why, if at all, should we object to economic inequality? Some central arguments – the argument from decreasing marginal utility for example – invoke instrumental reasons and object to inequality because of its effects. Such instrumental arguments, however, often concern only the static effects of inequality and neglect its intertemporal consequences. In this article, we address this striking gap and investigate income inequality's intertemporal consequences, including its potential effects on humanity's (very) long-term future. Following recent arguments around future generations and (...) so-called longtermism, those effects might arguably matter more than inequality's short-term consequences. We assess whether we have instrumental reason to reduce economic inequality based on its intertemporal effects in the short, medium, and the very long term. We find a good short and medium-term instrumental case for lower economic inequality. We then argue, somewhat speculatively, that we have instrumental reasons for inequality reduction from a longtermist perspective too, primarily because greater inequality could increase existential risk. We thus have instrumental reasons to reduce inequality, regardless of which time-horizon we take. We then argue that from most consequentialist perspectives, this pro tanto reason also gives us all-things-considered reason. And even across most non-consequentialist views in philosophy, this argument gives us either an all-things-considered or at least weighty pro tanto reason against inequality. (shrink)

How might we extend aggregative moral theories to compare infinite worlds? In particular, how might we extend them to compare worlds with infinite spatial volume, infinite temporal duration, and infinitely many morally valuable phenomena? When doing so, we face various impossibility results from the existing literature. For instance, the view we adopt can endorse the claim that worlds are made better if we increase the value in every region of space and time, or that they are made better if we (...) increase the value obtained by every person. But they cannot endorse both claims, so we must choose. In this paper I show that, if we choose the latter, our view will face serious problems such as generating incomparability in many realistic cases. Opting instead to endorse the first claim, I articulate and defend a spatiotemporal, expansionist view of infinite aggregation. Spatiotemporal views such as this do face some difficulties, but I show that these can be overcome. With modification, they can provide plausible comparisons in cases that we care about most. (shrink)

As is already well known, subjective consequentialists face a challenge which arises from the fact that many (perhaps even most) of the consequences of an action areunforeseeable: this fact makes trouble for the assignment of expected values. Recently there has been some discussion of the role of ‘indifference’ principles in addressing this challenge. In this article, I argue that adopting a principle of indifference to unforeseeable consequences will not work – not because of familiar worries about the rationality of such (...) indifference principles, but because subjective consequentialist theories which adopt such principles end up entailing either deontic indeterminacy or arbitrary deontic variance. This is because of another well-known fact: that possibilities do not ‘agglomerate’. (shrink)

Christopher Jay has recently argued that one version of subjective consequentialism is objectionable because it entails ‘arbitrary deontic variance’ in which the permissibility of some action can depend upon an arbitrary, non-moral choice of which possible results of the action to investigate or even reflect upon. This author argues that this deontic variance is actually entirely innocuous, and results from what may be the best subjective strategy for such investigation and reflection in cases involving uncertainty and cognitive limitations.