Utilitarianism and nonhuman animals have a noteworthy history. Jeremy Bentham was one of the first Western moral philosophers to take seriously the idea that species membership is morally irrelevant, and that anyone who can suffer morally matters for their own sake. In his book Introduction to the Principles of Morals and Legislation (1789), he writes: “The day may come, when the rest of the animal creation may acquire those rights which never could have been withholden from them but by the hand of tyranny.… [T]he question is not, Can they reason? nor, Can they talk? but, Can they suffer?”.1 In this short note, Bentham anticipated part of the trajectory that moral philosophy would take over the next 200 years.
More recently, Peter Singer helped to launch the modern animal protection movement in the West with his argument that all animals are equal. In his book Animal Liberation (1975), he writes, “there can be no reason – except the selfish desire to preserve the privileges of the exploiting group – for refusing to extend the basic principle of equality of consideration to members of other species”.2 He then describes how humans treat nonhuman animals in several industries, and he argues that we need to end these practices, building a more respectful and compassionate relationship with members of other species. The animal protection movement has been working to realize these ideals ever since.
This essay will explore the relationship between utilitarianism and nonhuman animals by examining three general issues. First, what does utilitarianism imply about the moral status of animals? Which animals count, and how much do they count? Second, what does utilitarianism imply about our moral duties to animals? Should we promote animal welfare, respect animal rights, or both? Third, what does utilitarianism imply about how we should achieve these goals? For example, how much should we prioritize animal welfare or rights over other important issues? What should we prioritize within the area of animal welfare or rights? And how can we effectively make progress in these areas?
While we will not be able to answer all of these questions in this short essay, we will note several important general trends. First, utilitarianism plausibly implies that all vertebrates and at least some 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 morally ought to attempt to both promote animal welfare and respect animal rights in many real-life cases. Third, utilitarianism plausibly implies that we should prioritize farmed and wild animal welfare and pursue a variety of interventions at once to make progress on these issues.
The Moral Status of Animals
Utilitarians accept a theory of moral status – that is, a theory of who morally matters for their own sakes – called sentientism. According to this theory, all and only sentient beings – that is, all and only beings who can consciously experience positive states like happiness or negative states like suffering – have moral status. Utilitarians also accept the principle of equal consideration of interests, according to which we morally ought to consider all interests equally when deciding what to do. In short, if someone is sentient, then they have interests. And if someone has interests, then we must extend equal consideration to their interests, no matter who they are, or which social or biological categories they happen to occupy.
This combination of sentientism and impartiality is part of why utilitarianism has historically been such a progressive theory. To this day, many people accept highly restrictive and hierarchical theories of moral status. For example, many people accept that only humans or rational agents morally matter. Many others accept that all sentient beings morally matter, but that some matter more than others; for instance, many people accept that members of some species, nations, and generations matter more than members of others, all else equal. In rejecting such views, utilitarianism commits us to expanding our moral circle much more widely than most human societies have done so far.
At the same time, utilitarians also accept that equal consideration is compatible with differential treatment. For example, insofar as different individuals have different interests, we might need to treat them differently to promote their welfare. Moreover, insofar as some individuals have stronger interests than others, we might need to prioritize the former individuals all else equal, to reflect the reality that they have more at stake. This kind of differential treatment is compatible with equal consideration because what matters is not that we treat everyone the same way or assign everyone the same moral weight, but rather that we treat like interests alike when deciding what to do.
Thus, to determine how much moral weight to assign to particular individuals, utilitarians need to establish which beings are sentient and how much happiness and suffering they can experience if they are. Unfortunately, these questions are difficult to answer because of the problem of other minds. In particular, since the only mind that we can directly access is our own, we might not always be sure whether someone else is sentient or how much happiness or suffering they can experience if they are. Instead, we might need to make estimates about what nonhuman minds are like by studying nonhuman anatomy, behavior, evolutionary history, and other such features.
Granted, it might seem like a bad idea to make estimates about what nonhuman minds are like. After all, our knowledge of nonhuman minds is limited not only by the problem of other minds, but also by a wide range of other biases. For instance, our ability to make reliable judgments about nonhuman minds appears to be limited not only by our collective self-interest but also by a general preference for animals with human-like features over animals with nonhuman-like features. But since these biases will likely affect our judgments about nonhuman minds no matter what, it can be useful to make these judgments explicit and then critically examine them, rather than simply leave them implicit as we normally do.
In any case, while we are still early in the process of assessing these issues, we can make a few general observations at present. First, we are in the midst of a rapid shift in attitudes about nonhuman minds in science and philosophy. For much of the last century, many experts denied that the study of nonhuman minds is a valid scientific pursuit, and they also denied that nonhuman animals have the capacity for conscious states of any kind. But in recent decades, many experts have started to accept that this topic is not only valid but also important, and they have also started to accept that many nonhuman animals have the capacity for a wide range of conscious states, including happiness and suffering.
Second, and in particular, there is an emerging consensus that, at the very least, all vertebrates – that is, all animals with a spinal column – are sentient. This category includes amphibians, birds, fishes, mammals, and reptiles. Thus, for example, it includes (a) 100+ billion farmed animals humans kill each year for food (mostly chickens and fishes), (b) hundreds of billions of wild animals humans kill each year for food (again, mostly fishes and other aquatic vertebrates), and (c) countless wild animals who suffer and die each year from natural causes such as hunger, thirst, illness, and injury, as well as from human causes such as agriculture, deforestation, development, pandemics, and climate change.
In contrast, there is not yet an emerging consensus about which invertebrates – that is, animals without a spinal column – are sentient. At one end of the spectrum, invertebrates such as octopuses have complex nervous systems, and many experts see them as likely to be sentient. At the other end, invertebrates such as sponges have no nervous systems at all, and so many experts see them as (very) likely to be non-sentient. In many other cases, evidence is more limited and mixed, and so there is more uncertainty. For example, insects have some features that suggest sentience and others that suggest non-sentience. Plausibly, the only reasonable stance that we can take about insects at present is that they might be sentient.
Now consider the question how much happiness and suffering someone can experience. In order to answer this question, we must first ask how much happiness and suffering someone can experience at any given time. This question is hard to answer as well. For instance, we might think that how much happiness and suffering you can experience at any given time depends in part on how many neurons you have. If so, then we might be able to compare how much happiness and suffering different animals can experience in part by comparing how many neurons they have. But this is unlikely to be a reliable approach, since many other factors, such as how our neurons are arranged, likely matter as well.
In order to determine how much happiness and suffering someone can experience, we must also ask how much happiness and suffering they can experience across time. This question is hard to answer as well. For instance, we might think that how much happiness and suffering you can experience across time depends on how much happiness and suffering you can experience at any given time, coupled with how long your life will be. But this might not be a reliable approach either. For instance, what if different animals experience the passage of time differently, such that a given week, month, or year feels longer to some animals than to others? We are only at the start of wrapping our minds around such questions.
But even if we are highly uncertain about whether particular animals are sentient or about how much happiness and suffering they can experience, we can still make rough estimates in order to make decisions about their treatment. For instance, suppose that we think that ants are anywhere from 20-40% likely to be sentient, and that they can experience anywhere from 10-20 units of happiness or suffering at a time, if any at all. In that case, utilitarians can use these probabilities and utilities to roughly estimate how much happiness and suffering ants can experience, in expectation. We can then incorporate these estimates into the harm-benefit analyses that we use to determine how to do the most good possible.
When we put all these ideas together, an interesting picture starts to emerge. According to this picture, larger animals with longer lifespans will tend to carry more weight on average, in expectation. After all, larger animals will tend to have more complex nervous systems, and, thus, will tend to be more likely to be sentient and to have the capacity for more happiness and suffering at any given time, in expectation. Similarly, animals with longer lifespans will tend to be able to experience more happiness and suffering across time, in expectation. As a result, for instance, if I have to choose between saving an elephant and saving an ant, I should save the elephant all else equal, on the grounds that they appear to have more at stake.
At the same time, smaller animals with shorter lifespans will tend to carry more (or at least a lot of) weight in total, in expectation. After all, there are many more small animals than large animals. For instance, there are hundreds of thousands of elephants at present, but there appear to be more than a quadrillion ants. So, even if ants might have a lower capacity for happiness and suffering than elephants on average, they might or might not have a higher capacity for happiness and suffering in total. And of course, (classical) utilitarianism is about total impacts, not average impacts. So it might be that large populations of small animals with short lifespans matter a lot in expectation, according to (classical) utilitarianism.
Moral Duties to Animals
According to utilitarianism, what moral duties do we have to nonhuman animals? Many people assume that utilitarianism supports promoting animal welfare rather than respecting animal rights, since utilitarianism is a welfare-based moral theory, not a rights-based moral theory. But even if utilitarianism favors welfare over rights in theory, it might or might not always favor welfare over rights in practice. It all depends on what approach will, in fact, maximize happiness and minimize suffering for all sentient beings. So the question for utilitarians is: To what degree can we improve the lives of animals by promoting animal welfare, and to what degree can we do so by respecting animal rights?
To answer this question, it helps to start by considering some general features of utilitarianism as a moral theory. First, at least in theory, utilitarianism is a highly demanding moral theory: It implies that we morally ought to do the most good possible for everyone impacted by our activity, including members of other species, nations, and generations. Thus, for example, utilitarianism does not imply that the distinction between domesticated animals and wild animals is intrinsically morally significant. Even if we are more responsible for the plight of domesticated animals than for the plight of wild animals, we morally ought to equally consider the interests of both kinds of animal when deciding what to do.
Second, at least in theory, utilitarianism is also a highly unrestrictive moral theory: It implies that we morally ought to do the most good possible by any means necessary. Thus, for example, if we need to harm or kill the few in order to help or save the many, then utilitarianism implies that we morally ought to do so, all else equal. Many people have used this reasoning in order to justify harming and killing animals in a wide range of contexts. And in principle, utilitarianism is consistent with this reasoning: While it prohibits unnecessarily violent practices such as factory farming, it might not only permit but require other violent practices, provided that these practices are necessary for doing the most good possible.
For these reasons, many people see utilitarianism as more demanding than many other moral theories in some respects and less demanding than many other moral theories in other respects, regarding other animals. On one hand, utilitarianism is more demanding because it implies that we have a moral duty to improve the lives of wild animals all else equal, whereas other moral theories typically do not. On the other hand, utilitarianism is less demanding because it implies that we might not always have a moral duty to abolish the use of animals for food, research, entertainment, and other purposes. Instead, it implies that such practices are not only permitted but required to the degree that they do the most good possible.
But while these claims are all correct in theory, matters are more complex in practice. In particular, many utilitarians believe that if we want to maximize happiness and minimize suffering in the world, then we might sometimes need to pursue this goal indirectly, not directly. Consider an analogy. If we want to be happy, then pursuing this goal directly might not work very well. Instead, we might need to pursue this goal indirectly, by thinking about what projects and relationships might make us happy, and then immersing ourselves in these projects and relationships in everyday life. Once we focus less on our own happiness and more on the activities that make us happy, we become more likely to achieve happiness.
Doing the most good possible is similar. If we want to achieve this goal, then pursuing it directly might not always work well, since we often lack the time, information, rationality, and motivation necessary to estimate what will achieve that goal and act on that information. Thus, we might sometimes need to pursue this goal indirectly, by thinking about what roles, rules, virtues, and so on might allow us to achieve this goal, and then focusing mostly on playing those roles, following those rules, cultivating those virtues, and so on in everyday life. As before, once we focus less on maximizing utility and more on the activities that allow us to achieve this goal, we become more likely to achieve this goal.
This point is important, because it creates a role for rights within utilitarianism. Granted, utilitarianism might imply that rights are, as Bentham famously declared, “nonsense upon stilts”3 in theory. But it might also imply that rights are important in practice, since we might need to extend moral, legal, and political rights to sentient beings in order to promote their welfare in practice. In this case, the idea that utilitarianism is about welfare, not rights, would be too simple. We should instead hold that utilitarianism is about welfare, not rights, in theory, and about both welfare and rights in practice. We should then attempt to promote welfare and respect rights together, rather than merely do one or the other.
Moreover, we have reason to believe that utilitarianism is, in fact, about both welfare and rights in practice. We currently live in a deeply speciesist society, where humans regularly discount the interests of nonhumans and use biased harm-benefit analyses to rationalize nonhuman exploitation and extermination. In this kind of context, the idea that animals have rights might be a necessary check on our tendency to harm, kill, and neglect them. This is why many utilitarians oppose killing one human to save five in practice, since it might erode our commitment to generally valuable rules, rights, and virtues. It might be that utilitarians should oppose killing one nonhuman to save five in practice for similar reasons.
When interpreted in this way, utilitarianism has different implications in practice than some people expect. For instance, some people see utilitarianism as committed to the “logic of the larder”. On this view, if farmed animals have net positive lives (that is, if they experience more happiness than suffering in the aggregate), then utilitarianism implies that we should support exploitation of these animals, in order to ensure that more animals with net positive lives come into existence. Yet many people see this implication as implausible: The fact that animals are expected to have net positive lives is not a good enough reason to bring them into existence and then harm and kill them against their will for our own purposes.
Similarly, some people see utilitarianism as committed to the “logic of the logger”. On this view, if wild animals have net negative lives (that is, if they experience more suffering than happiness in the aggregate), then utilitarianism implies that we should support extermination of wild animals, in order to ensure that fewer animals with net negative lives come into existence. Yet many people see this implication as implausible as well: The fact that animals are expected to have net negative lives is not a good enough reason to harm and kill them against their will. Indeed, many people think that we should leave wild animals alone even when intervening in their affairs would allow them to have longer or happier lives.
Generally, utilitarians respond to these objections in either of two ways. First, they insist that exploiting farmed animals, exterminating wild animals, and other such practices are not necessarily net positive. This might be true both because of the direct impacts on animals and because of the indirect impacts on public health and the environment. For instance, we might think that many farmed animals have net negative lives and that many wild animals have net positive lives. We might also think that the negative public health and environmental effects of animal agriculture and deforestation generate a strong presumption against these practices, in spite of the benefits that they might have for many animals.
Second, utilitarians insist that in cases where exploiting farmed animals, exterminating wild animals, and other such practices are net positive – for instance, because they create more animals with net positive lives or fewer animals with net negative lives, the benefits of these practices outweigh the harms, and no other option currently available would do as much good or as little harm overall – we are, indeed, not only morally permitted but also morally required to engage in these practices, all else equal. This result might be surprising, but as utilitarians regularly (and correctly) remind us, the point of moral theory is to critically assess our commonsense moral views, not simply rubber stamp them.
But once we allow that utilitarianism has a place for rights, we can offer an additional response to the logics of the larder and logger: If we want to do the most good possible, then we need to both promote welfare and respect rights in practice. This creates a presumption against activities that violate rights, including exploitation and extermination. Of course, this is not to say that we should never engage in such activities: If the stakes are high enough, then we should make an exception and break moral rules that we should ordinarily follow. But as a general matter, we should proceed on the assumption that humans and nonhumans alike have rights, and focus on promoting their welfare in ways that respect their rights.
Effective Animal Advocacy
Suppose that we accept this analysis. We morally ought to maximize happiness and minimize suffering in the world, and we can pursue this goal by promoting human and nonhuman welfare while respecting human and nonhuman rights. The question then becomes how we can achieve these goals effectively and efficiently. Utilitarians and other effective altruists answer this question by prioritizing issues that are important, neglected, and tractable, and by using evidence and reason to make progress on these issues. When we take this approach to animal welfare and rights, we discover that farmed and wild animals are particularly important, and that we can potentially help them in a wide range of ways.
Since there are many important causes in the world, utilitarians and other effective altruists need to prioritize in part by making cross-cause comparisons. They do that by comparing the importance, neglectedness, and tractability of different cause areas. In particular, they take a cause area to be a higher priority to the degree that (a) it impacts a greater number of individuals by a greater amount (importance), (b) fewer people are working on it (neglectedness), and (c) we can make a difference by working on it (tractability). By using this framework we can do much more good than we might otherwise do, since we would be working on the issues that allow us to make the biggest difference overall.
When utilitarians and other effective altruists apply this framework in practice, they generally arrive at the following top three global priorities. First, we should work to secure a positive future for sentient beings by attempting to increase the probability that we can have a future at all and that this future will be positive. Second, we should work to promote global health and development, for instance by distributing money and essential goods to people living in poverty. Third, we should work to promote animal welfare, for instance by working to reduce farmed and wild animal suffering. While there are many good causes, utilitarians and other effective altruists generally see these as the most important overall, at present.
As this description suggests, effective animal advocates – that is, utilitarians and other effective altruists who focus on animal welfare – generally see farmed and wild animal welfare as the top priorities within the animal welfare category. To see why, consider each in turn. First, farmed animal welfare is highly important, neglected, and tractable. Humans breed, raise, and kill more than 100 billion farmed animals each year and cause many of these animals to suffer profoundly. Relatively few people are working to reduce farmed animal suffering. And we have the power to reduce farmed animal suffering by reducing support for factory farming and increasing support for alternative food systems, as we will see.
Second, wild animal welfare is more important and neglected than farmed animal welfare, though it might also be less tractable. There are quintillions of wild animals alive at any given time who either are or, at least, might be sentient. The vast majority of these animals, if sentient, suffer and die prematurely as a result of natural causes such as hunger, thirst, illness, and injury, and human causes such as farming, fishing, deforestation, and development. And while many people are working to conserve species, hardly anybody is working to improve the lives of individual wild animals. However, we are currently not sure what if anything we can do to improve the lives of individual wild animals at scale.
In addition to knowing which issues to prioritize, we also need to know what we can do about those issues. Effective animal advocates are currently working on many promising projects, of which I will mention only a small sample. First, many effective animal advocates are pursuing institutional change by, for instance, supporting corporate outreach. Organizations like The Humane League work to improve farmed animal welfare by demanding that corporations improve treatment of broiler chickens and egg-laying hens. They also back up these demands with pressure campaigns designed to motivate corporations to make these commitments and to follow through on them.
Second, many effective animal advocates are pursuing legal and political change by, for instance, supporting groups that advocate for legal and political rights for animals and working to include animal welfare in impact assessments and policy decisions. For example, the Nonhuman Rights Project files lawsuits on behalf of nonhuman clients in the United States, in an effort to persuade courts to recognize their clients as legal persons with the capacity for legal rights. Whether or not these efforts succeed in the short term, they can generate discussion about animal rights, shift the overton window with respect to this issue, and pave the way for other kinds of social, legal, and political change for animals.
Third, many effective animal advocates pursue economic and technological change by, for instance, supporting the development of alternative proteins. Organizations like the Good Food Institute support the development of plant-based meat (that is, meat made out of plants) and cultivated meat (that is, meat made from a cell culture). These products are increasingly indistinguishable from conventional animal products, yet they cause much less harm to humans and nonhumans alike. If we can make these products more competitive on the market, for instance by improving their taste, price, and convenience relative to conventional animal products, then we can incentivize better food production and consumption patterns.
Fourth, many effective animal advocates pursue capacity building by, for instance, supporting the development of a broad, pluralistic animal advocacy movement. For example, Animal Charity Evaluators distributes money not only to a relatively small number of “top” and “standout” organizations through their Recommended Charity Fund, but also to a relatively large number of “promising projects around the globe” through their Movement Grants. The idea behind the latter fund is that we can make our work more effective overall when we support a variety of cause areas and interventions, so that we can continue to build knowledge, power, and political will in the movement over time.4
Finally, many effective animal advocates conduct, support, and promote research around animal welfare and advocacy. This is important for all areas, but is especially important for wild animal welfare, given how little we still know about what wild animals need and how we can help them. Thus, for example, the Wild Animal Initiative is working to support the development of welfare biology as an academic field. The idea behind this approach is that while we might want to be able to help wild animals as soon as possible, we can do much more good for them in the long run if we focus in the short term on determining how we can help them ethically and effectively.
But while many effective animal advocates see these approaches as promising, we must also keep an open mind about them. After all, utilitarianism and effective altruism are about doing the most good possible, not about supporting cause areas or interventions that we happen to personally like. So even if we, say, spend a decade working to improve the lives of farmed animals through corporate outreach, we should be prepared to switch to a new cause area or intervention if and when further information reveals that doing so is more promising overall. Pursuing particular projects while maintaining an open mind about which projects are best can be difficult. But it is also essential if we want our work to be effective.
Moving forward, utilitarians and other effective altruists will need to consider many other questions as well. For instance, sometime within the next century, we might share the world with sentient digital beings. How can we promote animal welfare and rights in a way that supports digital welfare and rights as well? Additionally, sometime within the next millennium, we might engage in interstellar travel and settle other worlds. How can we promote animal welfare and rights in a way that supports thoughtful decisions about which nonhumans to bring with us, how to interact with them, and how to interact with anyone else we might create or discover along the way?
We are only at the start of asking such questions, but the answers will be important. In general, it can be tempting to work on different cause areas separately, for instance by working on either existential risk mitigation, global health and development, or animal welfare. But the reality is that these cause areas are linked, not only because we need to prioritize between them but also because how we interact with humans and other animals in the short term will partly determine which problems our successors will face and which beliefs, values, practices, and institutions our successors will have in the long run. So, thinking about how these cause areas interact can help us make our work in each one more effective.
About the Author
Jeff Sebo is Clinical Associate Professor of Environmental Studies, Affiliated Professor of Bioethics, Medical Ethics, Philosophy, and Law, and Director of the Animal Studies M.A. Program at New York University. He is author of Saving Animals, Saving Ourselves (2022) and co-author of Chimpanzee Rights (2018) and Food, Animals, and the Environment (2018).
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Resources and Further Reading
- Driver, Julia (2012). Consequentialism. Routledge.
- John, Tyler and Jeff Sebo (2020). Consequentialism and Nonhuman Animals. Oxford Handbook of Consequentialism, ed. Doug Portmore. Oxford University Press.
- Sebo, Jeff (2019). Effective Animal Advocacy. Routledge Handbook of Animal Ethics, ed. Bob Fischer. Routledge.
- Singer, Peter (1975/2009). Animal Liberation: updated edition. HarperCollins Publishers.
- Woollard, Fiona (2021). ‘Utilitarianism for animals: deontology for people’ and the doing/allowing distinction. Philosophical Studies.
Bentham, J. (1789). An Introduction to the Principles of Morals and Legislation. Bennett, J. (ed.), p. 143. ↩︎
Disclosure: At the time of writing, I serve on the board of directors at Animal Charity Evaluators. ↩︎