Animal Ethics
Pablo Serra-Palao
Animal Ethics encompasses a diverse array of ethical approaches that draw from various ethical theories, including consequentialism, deontologism, and virtue ethics. It critically examines the relationship between humans and other animals, distinguishing between what is morally right or wrong and what should be considered as good or bad. In animal ethics, determining whether an action is morally right or good involves finding moral reasons to justify what we ought to do (or not to do) in our treatment of non-human animals. Hereafter, the term “animal” will refer exclusively to non-human animals.
Furthermore, animal ethics is regarded as a branch of applied ethics, much like bioethics, professional ethics, or the ethics of technology. As a result, contemporary literature in animal ethics focuses on specific moral issues, such as animal experimentation; animal labour power; wild animal suffering; the ethics of captivity; urban animals and city planning; or diverse challenges arising from biotechnological advancements. These challenges include, among others, genetic modification of animals for human health purposes, de-extinction projects within the context of rewilding, or the “genetic disenhancement” of animals for economic reasons (see Beauchamp & Frey, 2011; Fischer, 2020).
But besides specific moral dilemmas, the idea that moral agents ought to take animals into account in their moral deliberations depends on a fundamental question: do animals matter morally in their own right? This question refers to the moral status of animals, namely, that moral agents have direct duties toward an entity for her own sake (Metz, 2022, p. 149). As will be shown, an affirmative answer can take different forms. However, they all agree in rejecting a specific version of moral anthropocentrism, specifically the view that only human beings possess moral status.
It is also important to acknowledge that critical reflection on the relationship between humans and animals is not a contemporary phenomenon; rather, it has been present throughout the history of Western philosophy. In fact, several dissident voices in Greek philosophy challenged the dominant anthropocentric view. Notable examples include pre-Socratic thinkers such as Pythagoras and Empedocles, and later Plutarch and the Neoplatonist philosopher Porphyry. For instance, the Pythagorean tradition defended an “ethic of kinship with animals based on the doctrine of metempsychosis or transmigration of souls” (Steiner, 2005, p. 45). This belief in the reincarnation of the soul into other bodies —both human and animal—, rendered vegetarianism and benevolence toward animals as practices “conducive to the purification of the soul” (Steiner, 2005, p. 46). During the Early Modern period, Margaret Cavendish criticised the conception of the animal machine characteristic of Cartesian mechanicism in Philosophical Letters, published in 1664. A century later appeared An Introduction to the Principles of Morals and Legislation (1789), where Jeremy Bentham argued that the capacity of animals to suffer justified their protection against cruel treatment. It is also worth noting that in 19th-century Britain, numerous women took prominent roles in the animal protection movement —such as Frances Power Cobbe and her strong opposition to vivisection (Donald, 2020)—, and by the end of that century, Henry Salt published Animals’ Rights: Considered in Relation to Social Progress (1892). Moreover, critical reflection on human-animal interactions is also part of the history and ongoing discourse of non-Western philosophies and religions (see, for example, Linzey & Linzey, 2019; Metz, 2022, Ch. 8).
While several texts connecting animal protection to feminist demands were already circulating in the early 20th century, it was not until the 1970s that animal ethics emerged as a distinct philosophical discipline. A significant turning point in shaping animal ethics was Peter Singer’s Animal Liberation (1975). Guided by a utilitarian perspective, Singer argues that the principle of equal consideration of interests must be extended beyond the human species; thus, moral agents must give equal weight to interests of equal significance, irrespectively of the species. Consequently, a key point of this argument lies in identifying which entities possess interests: “the capacity for suffering and enjoyment is a prerequisite for having interests at all, a condition that must be satisfied before we can speak of interests in a meaningful way” (Singer, 1975/1999, p. 7). Singer is referring to the capacity of sentience, which can be defined as follows: “The capacity to have subjective experiences with positive or negative valence —experiences that feel bad or feel good— such as pain, pleasure, anxiety, distress, boredom, hunger, thirst, pleasure, warmth, joy, comfort and excitement.” (Browning & Birch, 2022, p. 1)
Since sentience constitutes both a necessary and sufficient condition for the possession of interests, it serves as the morally relevant criterion for having moral status. Therefore, favouring the interests of an individual solely based on their species membership would be a form of speciesism. This term refers to the “unjustified disadvantageous consideration or treatment of those who are not classified as belonging to one or more particular species” (Horta, 2010, p. 244). Current scientific and philosophical consensus suggests that all vertebrates, and some invertebrates such as cephalopods molluscs and decapod crustaceans (Birch et al., 2021), are sentient animals.
According to the previous approach, moral value resides in the interests at stake rather than in the specific individuals who possess them. In contrast, Tom Regan provided a different perspective on the moral relevance of animals, drawing inspiration from Kantian ideas. In the seminal work The Case for Animal Rights (1983), Regan argues that individuals who are “subjects-of-a-life” have inherent value, regardless of whether they possess moral agency (Regan, 1983/2016, pp. 290-294; see also Animal Agency). Possessing inherent value means that individuals must be treated with respect, and this duty is violated when they are treated “as if they were of instrumental value only” (Regan, 2003, p. 68). On this basis, Regan concludes that individuals with inherent value have a valid claim to be treated with respect. Since moral rights are valid claims, it follows that all subjects-of-a-life possess a basic moral right to be treated with respect (Regan, 2003, p. 73). Therefore, other specific rights would be based on this fundamental moral right, which is why Regan refers to his theory as a “rights view” (Regan, 1983/2016, Ch. 7 and 8; 2003, Ch. 6 and 7).
While the previous threshold was in the capacity of sentience, Regan’s theory shifts the focus to being a subject-of-a-life. The challenge lies in clearly defining which individuals satisfy this criterion, an aspect Regan himself acknowledged as incomplete (Regan, 1983/2026, p. 293). For Regan, being a subject-of-a-life entails, among other things, possessing a psychological unity consisting of beliefs, desires, and feelings; being in the world and aware of it; and having experiential well-being. In short, Regan refers to “beings with a biography, not merely a biology” (Regan, 2003, p. 80). In subsequent works following the first edition of The Case for Animal Rights (1983), Regan maintained that at least mammals and birds meet this criterion (Regan, 2003, p. 93).
In the 1990s, scholars began to problematise whether Singer and Regan, in their theoretical pursuit of abstraction, universalisation, and impersonality, had overlooked certain criteria that also deserved attention. Feminist scholars, including Josephine Donovan, Carol J. Adams, Greta Gaard, Marti Kheel, Deborah Slicer, Lynda Birke, or Lori Gruen (along with later scholars in Spanish-language literature such as Alicia Puleo, Marta Tafalla, and Carmen Velayos), began to recognise the significance of the relational and contextual in animal ethics. By placing the notion of care at the centre, they re-emphasised the emotional bond in the human-animal relationship and analysed the ways in which various forms of oppression and violence affect women, animals, and nature alike. This approach also created opportunities for dialogue between individualistic and holistic positions —previously seen as a significant divide between animal and environmental ethics— thus giving shape to an antispeciesist ecofeminism (see, among others, Adams & Gruen, 2022; Donovan & Adams, 2007).
Ultimately, these diverse perspectives converge on the premise that many current practices defining human-animal interactions are morally unjustifiable. This convergence is seen, for example, in the idea that adopting a plant-based diet is a moral duty. However, some ecofeminist views argue that an individual’s specific context might justify the use of animals for food or other purposes, a position known as “contextual moral vegetarianism” (Adams & Gruen, 2022; see also Veganism).
In conclusion, the 21st century has seen the animal question moving beyond moral philosophy into the realm of political philosophy and theory. These fields are using insights from animal ethics as a starting point to think about animals in political terms. This shift, often referred to as the political turn in animal ethics, entails reimagining political organisation for interspecies societies, which basically means discussing the three dimensions of justice (distributive, recognition, and participatory justice) beyond the human realm. A major contribution to this political turn is the book Zoopolis (2011) by Sue Donaldson and Will Kymlicka. Their proposal features three main characteristics: it is a relational theory, distinguishing between groups of animals based on their relationships with humans (namely, domesticated, liminal, and wild animals); it is based on the idea of moral rights, recognising universal negative rights for all animals (these are rights to non-interference, such as the right to life or the right to physical and psychological integrity) and differentiated positive rights depending on the group (i.e., rights to the provision of goods or services, such as the right to healthcare for domesticated animals); and finally, it is a political approach, as each group of animals holds a specific political status (citizenship for domesticated animals, denizenship for liminal animals, and sovereignty for wild animals) (Donaldson & Kymlicka, 2011). Additionally, legal philosophy has also explored how the moral rights articulated in Zoopolis could be legally argued. In this sense, Rey Pérez (2019) has specifically focused on the legal recognition of certain social rights for non-human citizens, such as extending labour right protections to animals working in various professional settings.
Bibliography:
Adams, C. J., & Gruen, L. (Eds.) (2022). Ecofeminism: Feminist Intersections with Other Animals and the Earth (2nd ed.). Bloomsbury.
Beauchamp, T. L., & Frey, R. G. (Eds.) (2011). The Oxford Handbook of Animal Ethics. Oxford University Press.
Birch, J., Burn, C., Schnell, A., Browning, H., & Crump, A. (2021). Review of the Evidence of Sentience in Cephalopod Molluscs and Decapod Crustaceans. LSE Consulting.
Browning, H., & Birch, J. (2022). Animal sentience. Philosophy Compass, 17(5), e12822. https://doi.org/10.1111/phc3.12822.
Donald, D. (2020). Women Against Cruelty: Protection of Animals in Nineteenth-Century Britain. Manchester University Press.
Donaldson, S., & Kymlicka, W. (2011). Zoopolis: A Political Theory of Animal Rights. Oxford University Press.
Donovan, J., & Adams, C. J. (Eds.) (2007). The Feminist Care Tradition in Animal Ethics. Columbia University Press.
Fischer, B. (Ed.) (2020). The Routledge Handbook of Animal Ethics. Routledge.
Horta, O. (2010). What is Speciesism? Journal of Agricultural and Environmental Ethics, 23(3), 243-266. https://doi.org/10.1007/s10806-009-9205-2.
Linzey, A., & Linzey, C. (Eds.) (2019). The Routledge Handbook of Religion and Animal Ethics. Routledge.
Metz, T. (2022). A Relational Moral Theory: African Ethics in and beyond the Continent. Oxford University Press.
Regan, T. (2003). Animal Rights, Human Wrongs: An Introduction to Moral Philosophy. Rowman & Littlefield Publishers.
Regan, T. (2016). En defensa de los derechos de los animales (1ª ed. electrónica). Fondo de Cultura Económica. (Original work published in 1983)
Rey Pérez, J. L. (2019). Los derechos de los animales en serio. Dykinson.
Singer, P. (1999). Liberación animal. Trotta. (Original work published in 1975)
Steiner, G. (2005). Anthropocentrism and its Discontents: The Moral Status of Animals in the History of Western Philosophy. University of Pittsburgh Press.