What Is Speciesism?

Direct Answer

Speciesism is the assumption that the interests of human beings matter more than the interests of nonhuman animals simply because they belong to the human species. The term was coined by the British psychologist Richard Ryder in the early 1970s and brought to global attention by Peter Singer in Animal Liberation (1975). Singer's central claim is that speciesism is a prejudice structurally parallel to racism and sexism: in each case, a morally irrelevant biological difference — skin color, sex, or species — is used to justify giving less weight to the interests of some beings. Because most animals can suffer and enjoy, they have interests that count morally, and the principle of equal consideration of interests requires that equal interests be weighed equally whatever the species of the being whose interests they are. If this is right, the standard practices of industrialized animal agriculture and animal experimentation cannot be defended merely by appeal to human benefit, since they impose enormous suffering on beings with an equal interest in avoiding it to satisfy comparatively trivial human preferences.

Historical Context

The Western tradition has long treated the species boundary as morally decisive. Aristotle's scala naturae arranged beings in a fixed hierarchy with humans above animals, and this picture passed through Aquinas and the scholastics into Christian ethics. Descartes radicalized it by denying that animals have minds at all, treating them as machines whose cries were mere reflexes. Kant located moral standing in rational autonomy, denying that we have direct duties to animals while insisting that cruelty to them is wrong because it hardens the heart toward humans. The utilitarians broke with this tradition. Jeremy Bentham posed the question that still frames the debate — "The question is not, Can they reason? nor, Can they talk? but, Can they suffer?" — and John Stuart Mill extended the greatest happiness principle to animals. Richard Ryder coined the word "speciesism" in 1970 within the Oxford animal-liberation circle, and Singer's Animal Liberation, published in the wake of the civil rights movement, gave the concept its enduring philosophical articulation.

Key Issues & Debates

The central dispute is whether species membership is itself morally relevant. Defenders of human priority argue that species differences track real differences in capacities — self-consciousness, rationality, moral agency — that ground higher moral status. Critics respond that the analogy with racism and sexism concerns equal consideration, not equal treatment, and that many animals rival or exceed some humans (infants, the severely cognitively disabled) in exactly the capacities invoked to justify human priority. A second debate concerns what equal consideration requires: Singer distinguishes equality of consideration from equality of treatment — comparable interests must count equally, but the treatment that respects them may differ. A third debate is the rights-based critique: Tom Regan argues that utilitarianism could in principle sanction sacrificing animals for a greater aggregate good, and that only inviolable rights can protect them. Finally, there is the scope question: whether speciesism condemns all killing of animals or only needless suffering, and how it bears on wild animal suffering, predation, and ecosystem management.

Contemporary Relevance

In 2026 the speciesism debate is more urgent than ever. Industrial animal agriculture still confines and kills tens of billions of sentient animals each year, even as plant-based and cultivated meat alternatives grow rapidly and legal systems in the European Union, New Zealand, and elsewhere formally recognize animal sentience and strengthen welfare protections. The climate crisis compounds the stakes: animal agriculture is a major driver of greenhouse gas emissions and land use, tying speciesism directly to climate ethics and consumption ethics. The rise of artificial intelligence opens a new frontier: as systems approach sentience-like capacities, the question of moral standing — and the risk of anthropocentric bias — moves from the farm to the laboratory. The effective altruism movement, inspired by Singer, treats farmed-animal welfare as one of the most neglected and tractable causes in the world.

Related Concepts

Speciesism sits at the center of a cluster of ideas in applied ethics: the equal consideration of interests, sentience as the criterion of moral standing, animal rights, wild animal ethics, and the ethics of consumption. It also intersects with the major normative traditions — deontology supplies rights-based constraints, virtue ethics asks what kind of people we become by how we treat animals — and with effective altruism, which asks how to do the most good with limited resources.

Further Learning

• Stanford Encyclopedia of Philosophy, "The Moral Status of Animals" — https://plato.stanford.edu/entries/moral-animal/
• Internet Encyclopedia of Philosophy, "Peter Singer" — https://iep.utm.edu/peter-singer/
• Peter Singer, Animal Liberation (New York: HarperCollins, 1975; rev. ed. 2009).