Books

The Moral Circle
(WW Norton, 2025)
In this book I argue that humanity should expand our moral circle — that is, our conception of which beings morally matter for their own sakes — much farther and faster than many philosophers assume, for two related reasons. First, we should be open to the possibility that a vast number of beings can be sentient or otherwise morally significant, including invertebrates and, eventually, artificial intelligences, and we should extend at least some moral consideration to these beings accordingly. Second, we should be open to the possibility that our actions can affect a vast number of beings, including beings who are far away in space and time, and we should extend at least some moral consideration to these beings accordingly as well. The upshot is that we should extend at least some moral consideration to septillions of beings, including and especially future nonhumans, with revisionary implications for many moral theories.
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Saving Animals, Saving Ourselves
(Oxford University Press, 2022)
In this book I argue that human and nonhuman fates are increasingly linked. Our use of animals contributes to pandemics, climate change, and other threats which, in turn, contribute to biodiversity loss, ecosystem collapse, and nonhuman suffering. As a result, we have a moral responsibility to include animals in health and environmental policy, by reducing our use of them as part of our pandemic and climate change mitigation efforts and increasing our support for them as part of our adaptation efforts. Applying and extending frameworks such as One Health and the Green New Deal, I call for reducing support for factory farming, deforestation, and the wildlife trade; increasing support for humane, healthful, and sustainable alternatives; and considering human and nonhuman needs holistically. I also consider connections with moral status, political status, creation ethics, population ethics, social services, infrastructure, and more. 
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Chimpanzee Rights (with other philosophers)
(Routledge, 2018)
In this book we make the case for chimpanzee rights. Under current US law, one is either a ‘person’ with the capacity for legal rights, or a ‘thing’ without the capacity for legal rights. And currently, all nonhuman animals are classified as things. Focusing on two captive chimpanzees, Kiko and Tommy, we argue that this approach to legal status is unacceptable. We consider the four main conceptions of legal rights and personhood that US courts have affirmed: a species conception, a social contract conception, a community conception, and a capacities conception. We argue that the species conception fails, and that the other conceptions, plausibly interpreted, are compatible with chimpanzee legal personhood. We conclude that if we continue to classify every being as either a person or a thing, then we should classify chimpanzees as persons, not things. We close by considering future directions for animal rights.
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Food, Animals, and the Environment (with Christopher Schlottmann)
(Routledge, 2018)
In this book we examine some of the main impacts that agriculture has on humans, nonhumans, and the environment, as well as some of the main questions that these impacts raise for the ethics of food production, consumption, and activism. Industrial animal agriculture is much more harmful than alternative food systems. It kills hundreds of billions of animals per year; consumes vast amounts of land, water, and energy; and produces vast amounts of waste, pollution, and greenhouse gas emissions. These impacts raise difficult ethical questions. What do we owe members of other species, nations, and generations? And what are the ethics of supporting and resisting unnecessarily harmful industries? The discussion ranges over topics such as effective altruism, abolition and regulation, revolution and reform, individual and structural change, single-issue and multi-issue activism, and legal and illegal activism.
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Articles

Towards a Global Ban on Industrial Animal Agriculture by 2050 (with Emma Dietz and Toni Sims)
Environmental Law (2024)
Industrial animal agriculture is both increasingly central to our global economy and increasingly harmful to humans, animals, and the environment, contributing to climate change, biodiversity loss, infectious disease emergence, antimicrobial resistance, and a variety of other problems. Fortunately, the global community has a long history of regulating products or processes that cause massive, unnecessary, and transboundary social, health, and environmental harms. By exploring precedents and instruments drawn from existing international law, this paper argues that a global ban on industrial animal agriculture is both possible and necessary to achieve alongside other global targets. It also proposes a pathway towards a global ban by 2050, which proceeds via informational, financial, regulatory, and just transition policies.
Draft Forthcoming

Taking AI Welfare Seriously (with Robert Long and eight other authors)
Independent Report
We argue that there is a realistic possibility that some AI systems will be conscious and/or robustly agentic in the near future. That means that the prospect of AI welfare and moral patienthood — of AI systems with their own interests and moral significance — is no longer an issue only for sci-fi or the distant future. It is an issue for the near future, and AI companies and other actors have a responsibility to start taking it seriously. We also recommend three early steps that AI companies and other actors can take: They can (1) acknowledge that AI welfare is an important and difficult issue (and ensure that language model outputs do the same), (2) start assessing AI systems for evidence of consciousness and robust agency, and (3) prepare policies and procedures for treating AI systems with an appropriate level of moral concern. 
Final Draft

Insects, AI Systems, and the Future of Legal Personhood
Draft Paper
This paper makes a case for insect and AI legal personhood. Humans share the world not only with large animals like chimpanzees and elephants but also with small animals like ants and bees. In the future, we might also share the world with sentient or otherwise morally significant AI systems. These realities raise questions about what kind of legal status insects, AI systems, and other nonhumans should have in the future. At present, debates about legal personhood mostly exclude these kinds of individuals. However, I argue that our current framework for assessing legal personhood, coupled with our current framework for assessing risk and uncertainty, imply that we should treat these kinds of individuals as legal persons. I also argue that we have good reason to accept this conclusion rather than alter these frameworks.
Rough Draft

Moral Circle Explosion
The Oxford Handbook of Normative Ethics (forthcoming)
In this chapter I argue that we should extend moral consideration to a much wider range of beings than we currently do. There are at least two reasons why. The first reason is epistemic: We should be open to the possibility that a very wide range of beings have moral status, and we should extend at least some moral consideration to these beings accordingly. The second reason is practical: We now have the power to impact a very wide range of beings, both within and across species, nations, and generations. The upshot is that we should extend at least some moral consideration to quintillions of beings – including invertebrates, plants, and some artificial intelligences – with revisionary implications for many moral theories.
Penultimate Draft

One Health and Multispecies Urban Infrastructure (with Alisa White and Toni Sims)
One Health and the Law: Existing Frameworks, Intersections and Future Pathways (forthcoming)
This chapter makes the general case for including animal welfare in local policymaking, with special focus on institutional and infrastructural change. We start by discussing the importance of animal welfare for the One Health framework, along with key questions about animal welfare. We then discuss general principles and policies that can guide cities in building multispecies urban infrastructure. For example, cities can implement bird-friendly building materials, improve road design and operation, provide guidance for incorporating animal shelter and habitat into green infrastructure, and shift their lawn maintenance practices. These and other policies have the potential to benefit humans, animals, and the environment alike.
Penultimate Draft

Are Individuals or Ecological Wholes What Matter? Yes.
Oxford Public Philosophy (2024)
There tends to be strong disagreement in animal and environmental ethics between individuals, who hold that individuals are the primary units of moral analysis, and ecocentrists, who hold that ecological wholes are the primary units of moral analysis. In this essay I suggest that the concept ‘primary unit of moral analysis’ is ambiguous, and that when we disambiguate it, we can identify a plausible view according to which individualists are correct in one sense and ecocentrists are correct in another sense. Specifically, in both science and ethics, we can make a distinction between the most basic units of analysis and the most helpful units of analysis, and we can say that smaller beings like individuals tend to be more basic but that larger beings like ecological wholes tend to be more helpful in many contexts. 
Final Draft

Climate Change, Public Health, and Animal Welfare: Towards a One Health Approach to Reducing Animal Agriculture’s Climate Footprint (with 6 co-authors)
Frontiers in Animal Science (2024)
This article argues that efforts to mitigate the climate impacts of animal agriculture should consider animal welfare and public health effects as well. We illustrate this point by discussing potential animal welfare and public health impacts of three popular approaches: (1) “sustainable intensification” methods, aimed at maintaining or increasing agricultural output while limiting emissions and land conversion; (2) “species shift” approaches, which focus on shifting diets away from consumption of high-emitting ruminants and towards animals who emit fewer GHG emissions; and (3) promoting shifts away from animal products altogether through systemic dietary change. We show that some of these approaches may introduce new, significant, and unnecessary risks to animal welfare and public health that merit consideration.
Final Draft

How Should Treatment of Animals Beyond the Lab Factor into Institutional Review? (with Laurie Sellars)
AMA Journal of Ethics (2024)
Discussions of nonhuman research ethics tend to focus on what we owe nonhuman research subjects in laboratory settings. But humans make critical decisions about these animals outside the lab, too, during breeding, transportation, and end-of-study protocols. This article reviews extra-lab risks and harms to nonhuman research subjects, focusing on the most commonly and intensively used animals like rodents and fishes, and argues that extra-lab risks and harms merit ethical consideration by researchers and institutional review. It then describes how different moral frameworks for assessing nonhuman subjects research might apply to current practices, and concludes that proper consideration of risks and harms beyond the lab would make animal research even harder to justify in many cases.    Summary
Final Draft, Summary

Overlapping Minds and the Hedonic Calculus (with Luke Roelofs)
Philosophical Studies (2024)
How should we update our moral thinking if it turns out to be possible for a single token mental state — a feeling of pleasure, displeasure, desire, frustration, or something else relevant to welfare — to belong to two or more subjects at once? Some philosophers think that such sharing of mental states might already occur, whereas others foresee it as a potential consequence of advances in neurotechnology and AI. Yet different types of case generate opposite intuitions: if two mostly-distinct people share a few mental states, it seems we should count the value of those states twice, but if two physically-distinct beings share their whole mental lives, it seems we should count the value of that life once. We suggest that these conflicting intuitions can be reconciled if the mental states that matter for welfare have a holistic character.
Final Draft

Wild Animal Welfare in Local Policies on Land Use and the Build Environment (with several authors)
NYU Guarini Center on Environmental, Energy, & Land Use Law (2024)
Experts increasingly agree that the health of humans, animals, and the environment are linked. As cities consider how to make their infrastructure more resilient and sustainable in the face of human-caused climate change, policymakers and other local actors have an opportunity to adopt new policies that can benefit humans, wild animals, and the environment at the same time. This first-of-its-kind policy brief describes how cities and other local actors can incorporate wild animal welfare considerations into their institutions, planning processes, and policies on land use and the built environment. The brief also identifies promising policy options for cities and other local actors to consider, ranging from bird-friendly building materials to green infrastructure design and prohibitions on gas leaf blowers.
Final Draft, Highlights

A Philosophers’ Letter in Support of Amahle, Mabu, and Nolwazi (with other philosophers)
An amicus letter submitted to the California Supreme Court (2023)
Under current U.S. law, one is either a ‘person’ or a ‘thing’. If you are a person, you have the capacity for rights. If you are a thing, you do not. And unfortunately, all nonhuman animals are currently considered things. In this letter, submitted as part of an appeal by the Nonhuman Rights Project, we make the case for elephant personhood. We consider the four main conceptions of personhood that U.S. courts have used to deny nonhuman personhood: a species conception, a social contract conception, a community conception, and a capacities conception. We argue that the species conception fails, and that the other three, plausibly interpreted, are compatible with elephant personhood. We conclude that if we insist on classifying every being as either a person or a thing, then we should classify elephants as persons, not things.
Final Draft

Considering Wild Animal Welfare in Benefit-Cost Analysis (with Toni Adleberg, Becca Franks, Adalene Minelli, Alisa White, and Katrina Wyman)
Public Comment to OIRA (2023)
The NYU Guarini Center on Environmental, Energy and Land Use Law and the NYU Wild Animal Welfare Program submitted a public comment to the Office of Management and Budget, Office of Information and Regulatory Affairs (OIRA) on its Proposed Guidance for Assessing Changes in Environmental and Ecosystem Services in Benefit-Cost Analysis. In this comment, we urge OIRA to ensure that the Guidance properly reflects (a) the instrumental value that animal welfare has for humans, (b) the intrinsic value that animal welfare has for the animals themselves, and (c) the importance that environmental changes can have not only for species and ecosystems but also for individual animals. We request that OIRA modify the Guidance to reflect these ideas, and in the event that OIRA declines, we request an explanation.
Final Draft

The Ethics and Politics of Meat Taxes and Bans (with nico stubler)
New Omnivorism and Strict Veganism (2023)
The harms of animal agriculture require policy changes to address. But there is substantial disagreement about what policy changes would be ethical and effective. This chapter will survey two general policy questions that we need to answer. First, should we focus on relatively moderate interventions such as taxes, or should we also pursue relatively radical interventions such as bans? Second, should we focus on taxing or banning particular kinds of animal products, such as factory farmed products, or should we pursue taxes or bans for all animal products? We will consider the ethical and strategic pros and cons of these approaches and argue that a mixed approach is likely best in practice. Along the way, we will consider many other relevant issues as well, such as whether meat bans are consistent with political liberalism.
Penultimate Draft

Esoteric Altruism: Does Effective Altruism Require Its Own Destruction?
Georgetown Journal of Law and Public Policy (2023)
A major difference between effective altruism and utilitarianism is that effective altruism is a practical project, not a moral theory. Effective altruists note that this status makes effective altruism less vulnerable to some objections to utilitarianism, such as the objection that utilitarianism is too demanding. However, this status might also make effective altruism more vulnerable to other objections to utilitarianism, such as the objection that utilitarianism is an “esoteric” moral theory that implies that nobody should accept it in practice. Plausibly, a moral theory can have this feature and still be correct. Can a practical project have this feature and still be correct? If so, why? If not, then a lot might depend on whether or not effective altruism is, in fact, esoteric in this sense. This essay examines how utilitarians reply to this objection and how effective altruists might be able to reply to it.
Final Draft

How Should We Improve How Medical and Veterinary Students Learn about Nonhuman Animals? (with Zoe Griffiths)
AMA Journal of Ethics (2023)
In this article, we present five general points that every clinician should know about animals, health, and the environment, focusing on why animals matter for their own sakes, why animals matter for health and environmental threats, and why health and environmental threats matter for animals, and how medical and veterinary schools interact with animals. We then offer practical advice about how to address these issues. For example, we propose that medical and veterinary schools increase coverage of animal welfare and the links between animals, global health, and the environment. We also propose that medical and veterinary schools support alternatives to animal farming and animal research to the extent possible. 
Final Draft

Integrating Human and Nonhuman Research Ethics
Bioethical Decisions (2023)
In this chapter I argue for developing a unified moral framework for assessing human and nonhuman subjects research. At present, our standards for human subjects research involve treating humans with respect, compassion, and justice, whereas our ethical standards for nonhuman subjects research merely involve (half-heartedly) aspiring to replace, reduce, and confine our use of nonhuman animals. This creates an unacceptable double standard and leads to pseudo-problems, for example regarding how to treat human-nonhuman chimeras. I discuss general features that a more integrated moral framework might have, assess the pros and cons of this kind of this framework, and argue that the pros decisively outweigh the cons.
Penultimate Draft

Intersubstrate Welfare Comparisons (with Bob Fischer)
Utilitas (2023)
In the future, when we compare the welfare of a being of one substrate (say, a human) with the welfare of another (say, an AI system), we will be making an intersubstratewelfare comparison. In this paper, we argue that intersubstrate welfare comparisons are important, difficult, and potentially tractable. The world might soon contain a vast number of sentient or otherwise significant beings of different substrates, and moral agents will need to be able to compare their welfare levels. However, this work will be difficult, because we lack the same kinds of commonalities across substrates that we have within them. Fortunately, we might be able to make at least some intersubstrate welfare comparisons responsibly in spite of these issues. We make the case for cautious optimism and call for more research.
Final Draft

Moral Consideration for AI Systems by 2030 (with Robert Long)
AI and Ethics (2023)
This paper makes a simple case for extending moral consideration to some AI systems by 2030. It involves a normative premise and a descriptive premise. The normative premise is that humans morally ought to extend moral consideration to beings that have a non-negligible chance, given the evidence, of being sentient or otherwise morally significant. The descriptive premise is that some AI systems do in fact have a non-negligible chance, given the evidence, of being sentient or otherwise morally significant by 2030. The upshot is that humans have a moral duty to extend moral consideration to some AI systems by 2030. And if we have a duty to do that, then we plausibly also have a duty to start preparing to discharge that duty now, so that we can be ready to treat AI systems with respect and compassion when the time comes. 
Final Draft 

The Rebugnant Conclusion
Ethics, Policy, and Environment (2023)
In this paper I consider some problems that small animals such as arthropods and nematodes raise for utilitarianism. In particular, if small animals have more expected welfare than large animals, then utilitarianism implies that we should prioritize the former all else equal. This could lead to a “rebugnant conclusion,” according to which we should create large populations of small animals rather than small populations of large animals. It could also lead to a “Pascal’s bugging,” according to which we should prioritize large populations of small animals even if these animals have an astronomically low chance of being sentient. I argue that the utilitarian should accept these implications in principle, but might be able to avoid some of them in practice.
Final Draft

Wild Animal Ethics
The Routledge Companion to Environmental Ethics (2022)
In this chapter I argue that we have a moral duty to improve the lives of wild animals, insofar as we can do so ethically and effectively. There are many more wild animals in the world than humans and domesticated animals, and many wild animals suffer and die unnecessarily as a result of natural threats, human threats, and mixed threats. For consequentialists, who think that morality is entirely a matter of consequences, we have a moral duty to help these animals because we have the power to reduce their suffering. For non-consequentialists, who think that morality is about more than consequences, we have a moral duty to help these animals because we are increasingly complicit in their suffering. Either way, we have duties of assistance to many more individuals than we might have thought.
Penultimate Draft

Clarifying the Ethics and Oversight of Chimeric Research (with 24 co-authors)
The Hastings Center Special Report (2022)
Researchers are currently using chimeras – nonhuman animals who contain human cells – to understand human disease and development, and to create human treatments and organs. This article makes ten recommendations about ethics and oversight of this practice. These recommendations concern the need to use clear language about this practice, the need to contextualize this practice within broader debates in science and ethics, the need to consider animal welfare and behavior, the need to share information both within and beyond the research community, and more. This article does not take a stand on whether chimeric use should happen, but instead examines how to oversee this practice in the event that it does happen.
Final Draft

Human, Nonhuman, and Chimera Research: Considering Old Issues with New Research (with Brendan Parent)
The Hastings Center Special Report (2022)
Researchers are currently using chimeras – nonhuman animals who contain human cells – to understand human disease and development, and to create human treatments and organs. As a result, bioethicists are now asking at what point chimeras become “human enough” to have human rights and thus benefit from higher standards of protection. However, these questions assume that the ethics of experimenting on nonhuman animals have been settled, which they have not. In this article, we argue that bioethicists should keep asking familiar questions about nonhuman animal research alongside new questions about chimera research, and that failure to do so will result in a distorted understanding of the ethics of chimera research.
Final Draft

Kantianism for Humans, Utilitarianism for Nonhumans? Yes and No.
Philosophical Studies (2022)
In this paper I argue that a two-level moral view, with a monist view at the theoretical level and a hybrid view at the practical level, is an attractive alternative to one-level monist and hybrid views. For example, both utilitarianism and rights theory, on a particular interpretation, imply a moderate “Kantianism for people, utilitarianism for animals” in practice. This kind of view preserves the benefits of monist views, since it allows for simplicity and unity at the theoretical level. It also preserves the benefits of hybrid views, since it allows for complexity and pluralism at the practical level. I also argue that this kind of two-level view is, to its credit, much more “pro-animal” in practice than the traditional “Kantianism for people, utilitarianism for animals.”
Final Draft

Mainstreaming Animal Welfare in Sustainable Development: A policy agenda (with several authors)
Stockholm+50 Background Paper (2022)
The lack of consideration of animal welfare in sustainable development policymaking has been an important oversight. Our current treatment of animals affects our ability to achieve the Sustainable Development Goals, and human-induced environmental challenges and our interventions to mitigate or adapt to them often affect animals. We identify three key pathways for mainstreaming animal welfare into sustainable development policymaking: (a) considering animal welfare in international policy; (b) improving national and local policies to promote animal welfare while ensuring other social, health and development goals are met; and (c) paving the way for additional action through research, capacity building, representation, and international cooperation.
Final Draft

Stockholm+50: Unlocking a Better Future (contributing researcher)
Stockholm+50 Official Independent Scientific Report (2022)
Looking back at the past 50 years, the world has changed in many ways – but not in the direction called for in June 1972 at the UN Conference on the Human Environment. This report synthesizes up-to-date scientific evidence and analyses the intertwined human and environmental crisis facing the world today. It presents key actions that can be taken now to seed transformative change and that are needed to redefine the relationship between humans and nature, ensure lasting prosperity for all, and invest in a better future. The report makes further recommendations for improving the conditions for change through improved policy coherence, strengthened accountability, and renewed multilateralism built on solidarity for our common challenges.
Final Draft

Sustainable Development Matters for Animals Too (with several authors)
CABI One Health (2022)
Animals matter for sustainable development, and sustainable development matters for animals. Yet animals remain neglected in sustainable development governance. The 2030 Agenda for Sustainable Development aims to protect species, biodiversity, and habitats, but not animal welfare. In June 2022, governments will convene for the UN Stockholm+50 Conference, which marks 50 years of international environmental decision-making. At this conference, world leaders have an opportunity to recognize the importance of animals for sustainable development, and to aspire to harm animals less and benefit them more as part of sustainable development governance. We call on world leaders to take these steps for the sake of humans and nonhumans alike.
Final Draft / Published Separately with 300+ expert signatories

Animals and Climate Change
Philosophy and Climate Change (2021)
In this chapter I argue that animals matter for climate change and that climate change matters for animals. In particular, animal agriculture will have a significant impact on the climate, and climate change will have a significant impact on wild animals. As a result, I argue, we morally ought to resist animal agriculture as part of our mitigation efforts and assist wild animals as part of our adaptation efforts. I also evaluate different strategies for accomplishing these aims, and I consider connections with debates about sentience and wellbeing, population ethics and duties to future generations, and the nature and limits of moral and political theory. I close by suggesting two ways forward: animal and environmental advocacy, and research on effective methods of reducing meat consumption and wild animal suffering.
Penultimate Draft, Purchase

One Health, COVID-19, and a Right to Health for Human and Nonhuman Animals (with Laurie Sellars and Kimberly Bernotas)
Health and Human Rights Journal (2021)
COVID-19 reveals the many interconnections between human and nonhuman health, welfare, and rights. Our treatment of nonhuman animals increases the risk of pandemics, and pandemics increase health risks for humans and nonhumans alike. Addressing these threats requires establishing a right to health for humans and nonhumans, and incorporating this right to health into public health frameworks such as One Health. In this paper we survey the case for a human and nonhuman right to health as well as the case for expanding One Health to include human and nonhuman health, welfare, and rights. We then survey the impacts that COVID-19 has had on nonhuman animals and suggest improvements to our public health response.
Final Draft / Reprint / Discussion / Discussion 

Towards Plant-Forward Diets: A Toolkit for Local Policy Makers (with Adalene Minelli, Danielle Spiegel-Feld, and Katrina Wyman)
NYU Guarini Center on Environmental, Energy, & Land Use Law (2021)
Reducing the consumption of meat would help to improve public health and reduce harms to animals and the environment. Cities – and other forms of local government, such as counties – are well-placed to facilitate the transition toward plant-forward diets. Indeed, they are fertile grounds for progressive policies and some cities already have implemented innovative policies to reduce meat consumption and other harmful practices. This policy brief identifies policies that cities are already using to reduce meat consumption, as well as novel policies that they could use to further their efforts. It also explores common constraints that city lawmakers face in making policy as well as some of the key areas of flexibility, and makes several general recommendations about how to proceed.
Final Draft

Utilitarianism and Nonhuman Animals
An Introduction to Utilitarianism (2021)
In this essay I advance three broad claims about relationship between utilitarianism and nonhuman animals. First, utilitarianism plausibly implies that all vertebrates and many invertebrates morally matter, and that large animals like elephants matter more on average and that small animals like ants might matter more in total. Second, utilitarianism plausibly implies that we should attempt to both promote animal welfare and respect animal rights in many cases in practice. Third, utilitarianism plausibly implies that we should prioritize farmed and wild animals over other nonhuman animals at present, and that we should work to support nonhuman animals through a variety of interventions, ranging from supporting the development of plant-based and cultivated meat to supporting the development of a field of welfare biology.
Final Draft

What Should We Agree on about the Repugnant Conclusion? (with many philosophers)
Utilitas (2021)
The Repugnant Conclusion is an implication of some approaches to population ethics. It states that for any population whose members have a very high quality of life, there must be a much larger population whose existence is better even though its members have lives only barely worth living. This conclusion has been the subject of several formal proofs of incompatibility in the literature and has been an enduring focus of population ethics. The Repugnant Conclusion served an important purpose in catalyzing and inspiring the pioneering stage of population ethics research. We believe, however, that this conclusion now receives too much focus. Avoiding it should no longer be the central goal driving population ethics research, despite its importance to the accomplishments of the existing literature.
Final Draft

Can Knowledge Itself Justify Harmful Research? (with David DeGrazia)
Cambridge Quarterly of Healthcare Ethics (2020)
In an earlier paper, we argue that animal research can be responsible only if it meets an expectation of sufficient net benefit condition (among other conditions). In response, Matthias Eggel, Carolyn Neuhaus, and Herwig Grimm object that this standard is too restrictive, since it might preclude approval of studies that can be expected to produce knowledge worth having. They also argue that this standard is too permissive, since it might permit approval of studies that cannot be expected to produce knowledge worth having. In response to the first objection, we deny that our standard is too restrictive. In response to the second, we allow for the possibility that our standard is too permissive but note that this issue raises challenging questions about the distinction between intended and foreseeable impacts.
Penultimate Draft

Consequentialism and Nonhuman Animals (with Tyler John)
The Oxford Handbook of Consequentialism (2020)
Consequentialism is thought to be in significant conflict with animal rights theory because it does not regard activities such as confinement, killing, and exploitation as in principle morally wrong. Proponents of the “Logic of the Larder” argue that consequentialism permits us to eat farmed animals with positive well-being to ensure future such animals exist. Proponents of the “Logic of the Logger” argue that consequentialism permits us to exterminate wild animals with negative well-being to ensure future such animals do not exist. We argue that this conflict is overstated. Once we have properly accounted for indirect effects, such as the role that our policies play in shaping moral attitudes and behavior, we can see that consequentialism may converge with animal rights theory significantly, even if not entirely.
Penultimate Draft, Purchase

Legal Priorities Research: A Research Agenda (with nine co-authors)
Legal Priorities Project (2020)
If we want to do the most good possible with limited resources, then we need to carefully consider which research areas to prioritize. In this document we discuss several legal research areas that we take to be especially high priority from a longtermist perspective. We start by discussing the foundations of legal priorities research, including our commitment to longtermism and our methodology. We then discuss four current high priority cause areas, namely, artificial intelligence, synthetic biology and biorisk, institutional design, and meta-research, as well as two cause areas that merit further engagement, namely space governance and animal law. We close with a discussion of relevant academic fields.
Final draft

The Philosophers’ Brief on Elephant Personhood (with other philosophers)
An amicus brief submitted to the New York Court of Appeals (2020)
Under current U.S. law, one is either a ‘person’ or a ‘thing’. If you are a person, you have the capacity for rights. If you are a thing, you do not. And unfortunately, all nonhuman animals are currently considered things. In this brief, submitted as part of an appeal by the Nonhuman Rights Project, we make the case for elephant personhood. We consider the four main conceptions of personhood that U.S. courts have used to deny nonhuman personhood: a species conception, a social contract conception, a community conception, and a capacities conception. We argue that the species conception fails, and that the other three, plausibly interpreted, are compatible with chimpanzee personhood. We conclude that if we insist on classifying every being as either a person or a thing, then we should classify chimpanzees as persons, not things.
Final Draft

Effective Altruism and Transformative Values (with L.A. Paul)
Effective Altruism: Philosophical Issues (2019)
Effective altruists attempt to use evidence and reason to do the most good that they can. However, many of our choices involve transformative experience, i.e. they affect our values in ways that we cannot fully anticipate. This limits our ability to make informed, rational decisions about long-term plans. In this chapter, we discuss the challenges and opportunities that decisions involving transformative experience pose for effective altruists. For example, how should I think about what career to pursue, given that this choice will affect who I am as a person? And, how should we think about how to engage with the public, given that these choices will affect who we are as a movement? We consider several possible answers to these questions, and we indicate where we think this discussion should head next.
Penultimate Draft, Purchase

Effective Animal Advocacy
The Routledge Handbook of Animal Ethics (2019)
Effective animal advocacy involves using evidence and reason to do the most good possible for animals. People who accept this framework tend to focus on issues such as farmed and wild animal welfare and on strategies such as corporate outreach and development of plant-based and cell-based meat. In this chapter I introduce this approach to animal advocacy and consider several objections. For example, is the goal of doing the most good possible too demanding? Is the strategy of focusing on corporate outreach and development of plant-based and cell-based meat too capitalist? I argue that effective animal advocacy has the right goal, and I propose strategies for pursuing this goal more effectively.
Penultimate Draft, Purchase

Activism (with Peter Singer)
Critical Terms for Animal Studies (2018)
In this chapter we discuss the past, present, and future of animal activism. For decades, animal activists have debated which strategies for helping animals are most effective. Some animal activists are now attempting to use evidence to resolve these disagreements. However, evidence-based animal activism raises concerns as well. For example, it could lead to a bias in favor of types of activism that aim for direct, measurable benefits and against types of activism that aim for indirect, less measurable benefits. The challenge, then, is to find ways to preserve the benefits of evidence-based activism while mitigating risk of bias as much as possible along the way. We make several provisional recommendations about how to do that.
Penultimate Draft, Purchase

The Ethics and Politics of Plant-Based and Cultured Meat
Les Ateliers de l’éthique/The Ethics Forum (2018)
In this paper I examine several of the moral and political questions raised by new kinds of meat. I begin by discussing the risks and harms associated with industrial animal agriculture, and I argue that plant-based meat and cultured meat are a promising alternative to conventional meat. I then explore the moral, conceptual, social, political, economic, and technical challenges that stand in the way of widespread adoption of these alternatives. For example, whether or not we achieve widespread adoption will depend on whether or not we can persuade business and political leaders to see plant-based and cultured meat as an opportunity rather than as a threat. Finally, I consider several ways of meeting these challenges, and I argue that we must be very careful if we want to avoid the kinds of problems that other, similar technological innovations such as GMOs have faced.
Final Draft

The Philosophers’ Brief on Chimpanzee Personhood (with other philosophers)
An amicus brief submitted to the New York Court of Appeals (2018)
Under current U.S. law, one is either a ‘person’ or a ‘thing’. If you are a person, you have the capacity for rights. If you are a thing, you do not. And unfortunately, all nonhuman animals are currently considered things. In this brief, submitted as part of an appeal by the Nonhuman Rights Project, we make the case for chimpanzee personhood. We consider the four main conceptions of personhood that U.S. courts have used to deny nonhuman personhood: a species conception, a social contract conception, a community conception, and a capacities conception. We argue that the species conception fails, and that the other three, plausibly interpreted, are compatible with chimpanzee personhood. We conclude that if we insist on classifying every being as either a person or a thing, then we should classify chimpanzees as persons, not things.
Final Draft

Fill-in-the-blank-emotion in Dogs? (with Alexandra Horowitz and Becca Franks)
Animal Sentience (2018)
What is needed to make meaningful claims about an animal’s capacity for subjective experience? Cook et al. (2018) attempt to study jealousy in dogs by placing them in a particular context and then seeing whether they display a particular brain state. We argue that this approach to studying jealousy falls short for two related reasons. First, the relationship between jealousy and the selected context is unclear. Second, the relationship between jealousy and the selected brain state (indeed, any single brain state) is unclear. These and other issues seriously limit what this study can show. It is important not to see this study as showing more than it does.
Final Draft

Fish Are Smart and Feel Pain: What about Joy? (with Alexandra Horowitz and Becca Franks)
Animal Sentience (2018)
The evidence of fish pain is now so strong and comprehensive that arguments against it have become increasingly difficult to defend in balanced academic discourse. But sentience involves more than just pain. Recent research indicates that fish have an impressive range of cognitive capacities, including the capacity for pleasure, in the form of play and other behaviors likely to involve positively valenced experience. Having made the case for pain, research can now focus on other aspects of fish sentience. Doing so will not only provide a more complete picture of the mental lives and abilities of fish, but it will also promote their welfare and protection.
Final Draft

The Moral Problem of Other Minds
The Harvard Review of Philosophy (2018)
In this paper I ask how we should treat other beings in cases of uncertainty about sentience. I evaluate three options: (1) an incautionary principle that permits us to treat other beings as non- sentient, (2) a precautionary principle that requires us to treat other beings as sentient, and (3) an expected value principle that requires us to multiply our degree of confidence that other beings are sentient by the amount of moral value that they would have if they were. I then draw three conclusions. First, the precautionary and expected value principles are more plausible than the incautionary principle. Second, if we accept a precautionary or expected value principle, then we morally ought to treat many beings as having at least partial moral status. Third, if we morally ought to treat many beings as having at least partial moral status, then morality involves more cluelessness and demandingness than we might have thought.
Final Draft / Discussion

Multi-Issue Food Activism
The Oxford Handbook of Food Ethics (2018)
Food activism sits at the intersection of many different social movements. The pluralistic nature of food activism has benefits as well as costs. For instance, it allows us to build alliances across movements, but it can also lead to conflict across movements. This article examines the debate between multi-issue food activism, which spans multiple movements and addresses multiple issues, and single-issue food activism, which does not. I begin by reviewing the kinds of connections across issues that are relevant here. I then present and evaluate two arguments for multi-issue food activism – one principled and one pragmatic – and three approaches to multi-issue food activism – unity, solidarity, and mutual understanding. Finally, I close with a few preliminary conclusions about how we can do food activism in a thoughtful and strategic way.
Penultimate Draft / Purchase

Agency and Moral Status
Journal of Moral Philosophy (2017)
According to our traditional conception of agency, most human beings are agents and most, if not all, nonhuman animals are not. However, recent developments in philosophy and psychology have made it clear that we need more than one conception of agency, since human and nonhuman animals are capable of thinking and acting in more than one kind of way. In this paper, I make a distinction between perceptual and propositional agency, and I argue that many nonhuman animals are perceptual agents and that many human beings are both kinds of agent. I then argue that, insofar as human and nonhuman animals exercise the same kind of agency, they have the same kind of moral status, and I explore some of the moral implications of this idea.
Final Draft / Discussion

Bivalves Are Better (with Jennifer Jacquet and Max Elder)
Solutions (2017)
The domestication of aquatic species is the fastest and most poorly thought out expansion of domesticated animals to ever occur. Many people are promoting aquaculture as replacing or at least supplementing wild, capture fisheries. A growing body of literature has assessed ecological concerns about aquaculture. Less consideration has been given to food security or animal welfare concerns. We argue that, if we are to culture aquatic animals (and that debate should remain open), we must include food security and animal welfare considerations in our deliberations so that we do not make the same mistakes as we did with terrestrial animals. We also argue that if our aim is to culture aquatic animals while minimizing negative ecological, food security, and animal welfare consequences, bivalves (e.g., oysters, mussels, clams and scallops) appear to be the species group with the most promise.
Final Draft

The Just Soul
The Journal of Value Inquiry (2015)
Many philosophers think that, if your “day self” and “night self” are physically, psychologically, and narratively continuous with each other, then they are the same unit of moral concern. But I argue that your day self and night self can share all of these relations and still be different units of moral concern, on the grounds that they can share all of these relations and still be in the circumstances of justice. I then argue that this conception of the scope of morality has revisionary, but ultimately plausible, implications for the morality of self-binding. For example, it implies that your day self and night self have a prima facie duty not to coerce or physically restrain each other in order to get what they want. But it also implies that they are morally permitted to coerce and physically restrain each other much more often, and with respect to many more issues, than, say, you and your friend are.
Penultimate Draft

Multiplicity, Self-Narrative, and Akrasia
Philosophical Psychology (2015)
In this paper I present a new account of akrasia based on the idea that human psychology and self-narrativity are more complex and layered than we have traditionally thought. I begin by arguing that, if we have at least some different beliefs, desires, preferences, etc. in different situations, then we can rationally do what we think, at the time of action, is best for, or from the standpoint of, “part of me” while acting contrary to what we think, at the time of action, is best for, or from the more comprehensive standpoint of, “me.” I then argue that many of us do, in fact, think and act this way in everyday life, and that this kind of action satisfies all the criteria for akrasia. Finally, I briefly argue that, on my account of akrasia, akratic actions are not necessarily irrational or blameworthy, though they often will be.
Penultimate Draft

Necessary Conditions for Morally Responsible Animal Research (with David DeGrazia)
Cambridge Quarterly of Healthcare Ethics (2015)
Animal research raises moral questions for several reasons. Nearly all animal research harms its subjects, animal subjects almost never benefit directly from their involvement in research, and animal subjects cannot give informed consent to their involvement in research. In this paper, we present three necessary conditions for ethical animal research that, we think, people on both sides of this debate can accept. Specifically, we argue that animal research is morally permissible only if it satisfies (a) an expectation of net benefit condition, (b) a worthwhile life condition, and (c) a no unnecessary harm / qualified basic needs condition. We then claim that, whether or not these necessary conditions are jointly sufficient, many animal experiments fail to satisfy them and are therefore morally wrong.
Penultimate Draft

Utilitarianism, Multiplicity, and Liberalism
Utilitas (2015)
In this paper I argue that utilitarianism requires us to tolerate intrapersonal disagreement for the same reasons that it requires us to tolerate interpersonal disagreement. I begin by arguing that multiplicity has many of the same costs and benefits as multiculturalism: it causes conflict, but it also allows us to perform experiments in living, adopt a division of labor, compartmentalize harm, and learn from ourselves. I then argue that, in light of these costs and benefits, utilitarianism requires us to adopt a “liberal system of individual self-government,” according to which we should not try to impose a single, unified set of beliefs and values on ourselves. Finally, I argue that we should apply this policy of liberal toleration to intrapersonal disagreement about utilitarianism too: if we want to maximize utility, then we should tolerate inner conflict not only about how to maximize utility but also about whether we should be trying to maximize utility in the first place.
Penultimate Draft

A Critique of the Kantian Theory of Indirect Duties to Animals
Animal Liberation Philosophy & Policy (2005)
Kant famously argues that we have no direct moral duties to animals; instead, we have only indirect duties to animals insofar as our treatment of them affects human beings. In this paper, I argue that Kantian ethics implies that we have direct moral duties to animals after all. I begin by arguing that the humanity formula of the categorical imperative, as normally interpreted, poses a problem: if rationality but not animality is an end in itself, then humans as well as nonhumans have only indirect moral status with respect to many of our activities. I then argue that we can solve this problem only by allowing that rationality as well as animality is an end in itself, from which it follows that humans as well as nonhumans have direct moral status. The upshot is that Kantian ethics, in order to protect the vulnerabilities of humans, must protect the vulnerabilities of nonhumans as well.
Penultimate Draft

Book Reviews

Shelly Kagan, How to Count Animals, more or less (2019)
Mind (2020)
Penultimate Draft

Christine Korsgaard, Fellow Creatures: our obligations to the other animals (2018)
Ethics (2019)
Penultimate Draft

Sarah Conly, One Child: Do We Have a Right to More? (2016)
Essays in Philosophy (2017)
Final Review

Tatjana Višak and Robert Garner (eds.), The Ethics of Killing Animals (2015)
Notre Dame Philosophical Reviews (2016)
Final Review

Works In Progress

The Discounting Defense of Animal Research
In this paper, I critique a defense of animal research recently proposed by Baruch Brody. According to what I call the discounting defense of animal research, our policy of favoring members of our own species is like our policy of favoring members of our own family, nation, and generation: It is not a morally impermissible case of discrimination but rather a morally permissible case of discounting. I argue, however, that none of the standard justifications for discounting supports favoring members of our own species in research. Indeed, if anything, these justifications support favoring members of other species in certain respects, especially given our history and legacy of harming nonhumans in research. The upshot is that we have strong prima facie reason to think that our preferential treatment of humans over nonhumans in research counts as discrimination rather than discounting.
Rough Draft

The Self as a Center of Psychological Gravity
In this paper I develop and defend a theory of the self that combines the simplicity of antirealism and the explanatory power of realism. I begin by critiquing two strategies that antirealists have used to achieve this goal. These strategies culminate in Dennett’s analogy with centers of gravity, the potential of which is only partially realized, I argue, in Dennett’s conception of the self as a center of narrative gravity. I then argue that we can fully realize the potential of this analogy, as well as vindicate the idea that the self is simple as well as explanatorily useful, if we say that the self is a center of psychological gravity, i.e., an abstract, simple set of psychological dispositions around which our actual, fluctuating psychological dispositions are “evenly distributed,” which we posit and aim to describe in our self-narratives for purposes of everyday psychological explanation, prediction, and control.
Rough Draft

Time-Slice Agency and Moral Responsibility
Many philosophers think that we are morally responsible for what we did in the past, and that this judgment supports the idea that our present self is the same basic moral agent as our past selves. I argue that this is a mistake: even if our present self is a different moral agent than our past selves, we can still be morally responsible for what we did in the past in many ways, e.g. we can still be complicit in, indirectly responsible for, criticizable for, and/or liable for what we did in the past. I then argue that this approach to personal responsibility, which analyzes personal responsibility on the model of interpersonal responsibility, explains and justifies our practice of holding each other responsible for different past actions in different ways at least as well as, if not much better than, more traditional approaches to personal responsibility do.
Rough Draft

Animals and Shared Agency
In this paper I argue that nonhumans can share agency in the same kind of way that humans can. I begin by making a distinction between “propositional agency,” which only humans have, and “perceptual agency,” which humans and nonhumans share. I then argue that perceptual agency allows for the same kind of structure that propositional agency does, and therefore, on a widely accepted account of shared agency, we can share both kinds of agency. For instance, if you and I walk together because we each intend to walk with the other, then we count as a shared propositional agent during our walk. Similarly, I argue, if my dog and I walk together because we each experience the other as to-be-walked-with, then we count as a shared perceptual agent during our walk. Finally, I argue that if nonhumans can share agency, then they can also share certain moral and political rights.
Rough Draft

A New, an Environmental Ethic
Many environmental ethicists think that our current, individualistic morality is hopeless in the face of global moral and political problems like climate change, and they argue that we should therefore replace it with a new, collectivist morality. I am inclined to agree with this idea. However, I also think that this call for a new morality is much more radical than we might have thought. In this paper, I argue that, if we want a new morality, then we have two options. First, we can accept an “esoteric morality.” That is, we can persuade others to accept a moral theory that we believe is false. Second, we can accept an “absurd morality.” That is, we can take a leap of faith and accept a moral theory despite believing that this theory is false. I consider the strengths and limitations of each approach and argue that they are well worth exploring all things considered, in light of the severity of our situation.

Time-Slice Agency and Numerical Identity
In this paper I develop and defend a time-slice theory of agent identity. I begin by arguing that there should be a presumption in favor of the idea that agent identity has the logic of numerical identity. I then argue that, if agent identity has the logic of numerical identity, then we have to choose between a time-slice theory of agent identity, on one hand, and a theory according to which basic agents persist for decades, on the other hand. Finally, I argue that, if we face this choice, then we should accept a time-slice theory of agent identity. The reason is that, if we accept this kind of theory, then we can invoke the distinction between basic agency (which does not come in degrees) and collective agency (which, in an important respect, does come in degrees) in order to explain and justify the widely accepted view that persons are temporally extended agents in a way that comes in degrees.

Wildness and Civilization (with Maryse Mitchell-Brody)
In this article we argue that there is a tension between maintaining order and respecting difference that we see especially clearly in the case of “disorderly” human and nonhuman animals. In the past, political actors have responded to this tension by locking “disorderly” individuals away. We argue that this response is unjust, and we examine the implications for political philosophy. Specifically, it is an open question whether liberal theories of justice, which emphasize the value of stability as well as the value of toleration, have the resources to accommodate the sheer variety of experience we now see among beings who seem to merit political inclusion. We survey possible answers, and we claim that any adequate answer will likely involve either relaxing our conception of the circumstances of justice or admitting that we were never in the circumstances of justice in the first place.

Dissertation

The Personal Is Political
Committee: Derek Parfit, John Richardson, Sharon Street, J. David Velleman (chair)
I argue that Plato was right that we should use political morality as a model for personal morality. Many people have multiple personalities, in the non-pathological sense that we have at least some different thoughts, feelings, and habits in different contexts. For example, you might think, feel, and act one way around family, another way around friends, and another way around colleagues. I argue that each personality is a distinct moral agent, with a distinct set of reasons, duties, and rights. Thus, I argue, many people are like states: They are communities of moral agents who share resources and a common fate. I then pursue the analogy with the state with respect to issues such as integrity, justice, sovereignty, and responsibility.
Final Draft