Angie Pepper, University of Roehampton

ORCID 0000-0002-2608-667X

Assigned DOI doi.org/10.3998/jpe.10746

Abstract

Jonathan Birch's 'Ethics for a Large Sentient World' presents a novel approach to the challenges associated with granting sentient insects direct moral concern. The Gandhian-inspired ethic that Birch develops takes insect sentience seriously while maintaining that insects have no right not to be harmed when harming them is necessary to secure human and nonhuman animal health and agricultural benefits. This paper offers a critical response to Birch's framework. I begin by arguing that Birch misinterprets the challenge facing a robust rights-based theory. I then show that his Gandhian alternative is not a genuine departure from a robust rights-based view but rather a specific, and ultimately unappealing, version of it. I show that Birch's view is unattractive because it holds that duties of care can function as exceptions to rights, which has problematic implications for all sentient beings, including humans.

Keywords

sentience, rights, insects, rights conflicts, specificationism, animal ethics.

Much contemporary animal rights theory assumes that insects are not sentient. Yet, in practice, many animal rights theorists are vegan and considerate of insects in their daily lives. For instance, we eschew honey, avoid foods containing cochineal dye, are sceptical of the morality of farming insects for food, and largely try to avoid doing deliberate harm to insects. Why is there this disconnect between what we write and how we live? As one of those who has dismissed insect interests in writing, but behaves as though those creatures are sentient in everyday life, I think the answer is “strategy”. The “insect challenge”, as Jonathan Birch describes it, has often served as a reductio to animal rights theory and advocacy: if we grant rights to dogs, cows, and dolphins, then we must do the same for ants, mosquitos, and ladybirds. Ergo, the whole enterprise is preposterous!

In response to the insect challenge, animal rights theorists have by and large betrayed insects. “No, no” we say, “we only have direct moral duties to sentient beings, and since insects probably aren’t sentient, they don’t count”. Importantly, this argumentative strategy only excludes insects by ceding the popular assumption that insects are not sentient. Few animal rights theorists have spent time defending that claim, and most views include the following caveat: if it turns out that insects are sentient, then the account will naturally extend to those beings.

Birch suggests that Western analytic animal rights theory cannot be made to work for insects. Of the four options that he canvasses and finds wanting, option 4 is roughly the one that I and many other animal rights theorists are implicitly committed to. It is the view that “all sentient beings, including the insects targeted by public health, veterinary and agricultural interventions, have robust rights, including a right not to be harmed” (2026). Birch rejects this view because he takes it to require the discontinuation of insecticide-treated malaria nets and insecticides in agriculture. This is because insecticides cause suffering, and if insects have a right not to be harmed then we cannot permissibly use insecticides to protect ourselves and our crops against them.

Birch advocates instead for a turn towards an ethic that is Gandhian in spirit. This ethic promotes nonviolence to all sentient beings and yet recognises that violence is unavoidable: we cannot care well for those who matter to us without perpetrating some violence against others. On the view Birch defends, this violence can only be justified when needed to satisfy the binding duties of care that attach to social roles compatible with the path of ahimsa – those social roles consistent with a commitment to live a life of nonviolence whenever possible (2026).

Should we endorse the Gandhian framework that Birch offers us over a robust rights view? While the proposed alternative is certainly interesting, I will argue that we should not. First, I suggest that Birch misrepresents the challenge facing a theory of robust rights for all sentient beings. Second, I observe that the Gandhian framework doesn’t represent a genuine alternative to a robust rights-based view, rather it is a particular version of such a view. Third, I argue that the version Birch offers is unattractive. Specifically, I suggest that the distinctiveness of the Gandhian position lies in the claim that duties of care function as exceptions to rights, but this has troubling implications for all sentient beings, including us.

Rights in Conflict

Let’s begin with the way that Birch characterises existing animal rights theory and the challenge that insects pose. In his discussion of the four options, Birch suggests that robust rights are “rights not easily overridden by human interests” (2026). He then goes on to suggest that robust rights prohibit the use of insecticides, implying that such rights cannot be overridden by significant human interests. This doesn’t fit well with how many rights theorists think about rights: while I cannot justifiably override your right to satisfy some trivial interest, I may be permitted when more fundamental interests are in competition. Rights are not absolute, and rights conflicts are prolific even when we consider only human beings.

For example, I may only be able to rush you to hospital for life-saving treatment if I borrow someone’s car without their permission; a doctor may need to decide which of her hundred patients she will assist, given she only has resources to treat some of them; the state may only be able to satisfy its duty to keep us safe by increasing essential national defence spending at the expense of welfare spending, and so on. Indeed, conflicts are arguably an intractable and persistent feature of moral life that need to be negotiated (Waldron 1989).

When faced with conflicts between rights, we must make tough choices about which interests to prioritise. The conflicts that Birch envisages between human and insect interests are of this kind. The interests of humans in not being infected with malaria or suffering malnutrition due to crop failure are not trivial; they are fundamental interests central to well-being. Consequently, the rights of insects are not “easily” overridden, but instead come into conflict with fundamental human interests. Hence, we face a difficult choice between protecting the rights of humans to good health and nutrition and protecting the rights of insects to not be harmed and killed.

Birch doesn’t seem to allow that rights may conflict. This is initially puzzling because it is an obvious move available to animal rights theorists working in the Western analytic tradition. However, a closer look at his own position explains why this option is absent from the option space as he characterises it. According to the Gandhian framework Birch offers us, “all plausibly sentient beings, including insects, have a right not to be harmed unless specified exceptions apply” (2026). From this, I think we can interpret Birch’s view as a version of option 4 insofar as it holds that insects targeted by public health, veterinary and agricultural interventions, do have robust rights in some circumstances such as when they would be the victims of gratuitous violence. However, he maintains that there are exceptions to their rights, that make the use of insecticides sometimes permissible.

This way of thinking about rights is known as ‘specificationism’. Specificationists maintain “that each right is defined by an elaborate set of qualifications that specify when it does and when it does not apply” (Wenar and Cruft 2025). Consequently, specificationism denies that rights can conflict because they're so precisely defined that all exceptions are built directly into their content. I think his implicit commitment to specificationism explains why Birch does not consider how a robust rights view can, in fact, permit the use of insecticides while also recognising that the insects in question have been wronged. It prevents him from seeing that insects could have robust rights which are, nonetheless, justifiably overridden by human interests—much like how human rights can sometimes be overridden by other significant, competing interests.

Why We Should Reject Specificationism

It's worth noting that specificationism faces several significant problems. First, fully defining a right with all its exceptions is incredibly difficult, if not impossible. Consequently, the right itself loses its practical role in our decision-making because we end up reasoning about the potential exceptions rather than from the right itself. This is why, for the specificationist, a right can only ever be a conclusion—reached after we've checked all the exceptions—and never a premise in our moral arguments (Wenar and Cruft 2025). Another problem is that specificationism offers no satisfactory answer to the ‘moral residue argument’ (Thomson 1990, p. 84). Imagine that through no fault of your own, you endanger my life, and I can only save myself by paralysing you. A specificationist would claim that if my action is permissible, you have no right against being paralysed and, therefore, will not be wronged. Moreover, you are owed no apology or compensation, as I've done nothing that would warrant either. This absence of ‘moral residue’ in the specificationist view—despite the intuitive sense that a wrong occurred—is implausible. Like many others, I reject specificationism because it renders rights practically inert in our deliberations, fails to adequately capture our moral experience, and renders genuine moral dilemmas impossible.

A rival view, known as generalism, holds that rights are general, defeasible moral principles. While rights act as stringent moral constraints, they can be justifiably infringed upon in cases of genuine conflict. An important feature of this view is that such infringements, though justified, nonetheless constitute a wrong against the right-holder.

I believe we should prefer generalism over specificationism because it better preserves the role of rights in our practical reasoning. Generalism allows rights to function as premises in our moral arguments. So, in reasoning about what to do, generalism allows us to say, “It is wrong to do X, because Y has a right that we don't do X”. The specificationist, by contrast, must treat this statement as a conclusion, one that is reached only after we have considered all the circumstances and determined that none of the pre-defined exceptions to the right apply.

Generalism is also able to account for the moral residue that remains after a justified infringement. In a genuine moral conflict, a generalist can argue that while it may be permissible to infringe someone's right, the right itself doesn't simply vanish into thin air. Rather, the infringement produces a ‘moral remainder’ that generates further duties, such as the need for apology, compensation, or measures to prevent similar conflicts in the future. As Jeremy Waldron writes, “an individual's right does not simply disappear from view once it has been traded off against the rights of others […]. It remains in the picture and must be taken seriously as a residual source of other duties and obligations” (1989, p. 512).

Infringing Insect Rights

Can a case to be made in favour of infringing the rights of insects to prevent malaria in humans or crop destruction? I cannot defend a full view here, but it will suffice to show that conflicts can occur and that insect interests may not always win out. We might for instance argue for any of the following: the harm of death is greater for more cognitively complex beings; the suffering experienced by insects is less bad than the suffering experienced by more cognitively complex beings; when insects pose a significant threat to life or health, we can permissibly prioritise ourselves or others to kill or harm them to avert the threat. Crucially, when we face tragic choices – a dilemma in which all possible resolutions involve infringing someone or other’s rights – it is appropriate to consider whether the relative shape and weight of the interests concerned is morally relevant. Where there are differences, those differences may play a role in our reasoning about how to balance the competing claims.

None of this means that we can do what we like to insects or that their rights are easily overridden. First, their rights cannot be infringed to satisfy our trivial interests such as when we find don’t like their behaviour or we judge them to be nuisance. We might not like their buzzing, crawling on our skin, or eating our garden plants, but that does not give us license to harm them. We may seek nonharmful ways of deterring these animals but when those fail, we must respect their rights to not be harmed and killed. Second, where their rights conflict with the rights of other sentient beings, including humans, and we are permitted to infringe those rights, they are nonetheless wronged by that action. This explains why we have ongoing duties to do better with regard to insects. While we may be permitted to harm them to protect crops and human health, the fact that we infringe their right not to be harmed demands that we actively work to find alternatives and they have a moral complaint if we fail in our remedial duties to avoid future wrongs.

A final thing that’s worth pointing out is that not all conflicts are natural. Rather, many conflicts between human and nonhuman animal interests are manufactured by us (Francione 2008). Consider flea treatments for pet dogs, which Birch himself discusses as a justifiable use of insecticides (2026). These chemicals pose considerable risks of harm and death to other sentient animals, not just those who are targeted but the many that live in and depend upon our rivers (Perkins et al 2021). What we should note here is that the conflict principally arises because we keep dogs in our homes in the first place. By ending the practice of keeping dogs as pets, we would reduce need to treat dogs with insecticides and the attendant harms that these treatments cause to insects and other creatures.

Exceptions to Rights in the Gandhian Framework

So far, I’ve suggested that Birch’s view might plausibly be interpreted as a robust rights view that is specificationist in nature, which perhaps explains why he doesn’t consider the possibility of addressing the insect challenge by appeal to the idea of justified rights infringements. I’ve also suggested that specificationism is unattractive and that generalism provides us with better tools to make sense of the conflicts we face. Let’s now consider the most distinctive feature of Birch's Gandhian ethic: his account of exceptions to rights.

Birch states that insects have a right not to be harmed except when moral agents have “duties of care (to oneself or others) taken on when adopting social roles compatible with a sincere commitment to the path of ahimsa” (2026). This means that when insect interests in not suffering conflict with our duties to protect or satisfy interests in food or good health, then we are permitted to use insecticides because the insects do not have a right against us.

This story should give us pause. While Birch is at pains to show that the Gandhian ethic has the resources to rule out “spurious or illusory duties of care” (2026), the view nonetheless involves a commitment to an unconstrained and morally unpalatable form of partiality. Birch explicitly says, “A striking aspect of the view is that numbers have no role. If an exception applies, then, beyond the injunction to harm ‘as little as possible’, there is no upper limit to the number of animals that may be killed. If we must kill a million insects to fulfil our duties of care, we may” (2026).

We might not initially object to this when applied to insects, given our typical disregard of their interests. However, if this framework is intended as a general moral theory—not merely a solution to the insect challenge—its implications are deeply troubling for the humans and other animals we happen to value. Consider, for instance, that such a view would permit me to kill five, a hundred, or even a million children to save my own, solely because I have a duty of care to my child that I do not owe to the others. This is deeply counterintuitive and signals that the Gandhian account of exceptions has gone awry.

Here's why. A moral framework that makes our entitlements contingent upon others’ relations of care is unattractive because it unacceptably diminishes the space of moral protection for those who are unloved and uncared for. In a system where rights can be extinguished by duties of care, individuals who lack such relationships—the neglected, the orphaned, the stigmatised, or simply those outside a specific circle of affection—become morally vulnerable. Their well-being and very existence are rendered secondary to that of others, not due to any fault of their own, but merely because they are not the object of someone else's specific duties of care. Of course, we don’t want to rule out partiality altogether, but we ought to resist views that claim that a person’s basic right not to be harmed can disappear when others are in special relationships that ground duties of care.

Second, and perhaps more fundamentally, such a view compromises the universal and impartial protection that rights are supposed to afford. Irrespective of how much an individual is cared for, their rights should not simply vanish because another person has a duty of care that would conflict with those rights. If my right to life, for example, can be extinguished merely because your duty to care for someone else requires it, then rights lose their capacity to provide a consistent sphere of moral protection. This understanding of rights as potentially “blinking out of existence” in the face of conflicting duties of care undermines their very purpose as universal entitlements that protect fundamental interests.

A more attractive rights-based view grounds the source of rights conflicts, first and foremost, in the competing interests at stake, rather than the caring responsibilities attached to specific roles. This is not to deny that special relationships can influence the rights we have or justify certain infringements, as we often possess important interests within these relationships. Nevertheless, at its root, our moral entitlements should track what is essential to the well-being of each of us as sentient creatures.

Concluding Thoughts

While animal rights theorists have admittedly failed to deal with the insect challenge, that’s no reason to think we don’t have resources to bring insects within the sphere of those to whom we have direct moral duties. Such inclusion will increase moral conflict. But that is no reason to favour the Gandhian ethic advanced by Birch. Accepting that tragedy is a feature of moral life is much less costly than adopting a moral framework saddled with the problems associated with specificationism and an unattractive view about the grounds of rights exceptions.

Of course, much more needs to be said, not least of all because it is plausible that sentient insects have many other interests besides not being harmed. For example, there is evidence of planning and tool use in insects, and evidence that they have preferences, which suggests that they have the capacity for, and thereby an interest in self-determined action. Moreover, many insects are social creatures, and as such might have significant interests in living with conspecifics or in having privacy. Some are also expert architects and builders who may have important interests in property and territory. These observations suggest that we are only at the beginning of determining what we might owe to those who have for too long been denied any consideration at all.

Acknowledgements

I would like to thank Rich Healey and Jonathan Parry for helpful conversation and written feedback on earlier drafts.

References

Birch, Jonathan. 2026. 'Ethics for a large sentient world: Insects, ahimsa, and Gandhi's progressive ahimsaism', Journal of Practical Ethics 13 (2) 

Francione, Gary. 2008. Animals as Persons: Essays on the Abolition of Animal Exploitation. New York: Columbia University Press.

Perkins, Rosemary, Martin Whitehead, Wayne Civil, and Dave Goulson. 2021. ‘Potential Role of Veterinary Flea Products in Widespread Pesticide Contamination of English Rivers’, Science of The Total Environment 755: 143560.

Thomson, Judith Jarvis. 1990. The Realm of Rights. Cambridge, MA. Harvard University Press.

Wenar, Leif and Rowan Cruft. 2025. ‘Rights’, The Stanford Encyclopedia of Philosophy (Summer 2025 Edition), Edward N. Zalta & Uri Nodelman (eds.), URL = <https://plato.stanford.edu/archives/sum2025/entries/rights/>.

Waldron, Jeremy. 1989. ‘Rights in conflict’, Ethics 99 (3): 503-519.