Speciesism

Quick answer: Speciesism is the idea — or practice — of giving less moral weight to someone’s interests simply because they belong to a different species, for example treating a pig’s suffering as less important than a dog’s or a human’s for no reason other than species. The term was coined by the psychologist Richard Ryder while campaigning in Oxford in 1970 and popularised by philosopher Peter Singer, who compared it to racism and sexism. Opposing speciesism is one of the main philosophical arguments for veganism.

Key facts

• Definition: “the practice of treating members of one species as morally more important than members of other species” (Britannica).
• Origin: Richard Ryder coined the term in the 1970s “while campaigning in Oxford”, and Singer popularised it (Stanford Encyclopedia of Philosophy).
• Core principle: Singer’s equal consideration of interests — comparable interests, such as avoiding pain, deserve equal weight whoever has them.
• Key debate: the “argument from marginal cases”, which challenges using capacities such as rationality as the basis for moral status (Stanford Encyclopedia of Philosophy).
• Science: the 2024 New York Declaration on Animal Consciousness states there is strong scientific support for conscious experience in mammals and birds and at least a realistic possibility in all vertebrates and many invertebrates (NYU).
• Speciesism in practice: the different treatment of companion animals and farmed animals, and laws classing animals as property.

Speciesism is the practice of treating members of one species as morally more important than members of other species, solely on the basis of species membership, in situations where the difference in treatment is not justified by relevant differences. The term is used mainly by critics of such treatment, and the concept plays a central role in arguments for animal rights and ethical veganism.

Origin of the term

The word was coined in 1970 by the British psychologist Richard D. Ryder, who used it in a privately printed leaflet while campaigning in Oxford (Stanford Encyclopedia of Philosophy) to draw a parallel between discrimination against animals and other forms of prejudice such as racism and sexism. The term was popularised by the philosopher Peter Singer in his book Animal Liberation (1975), which became one of the foundational texts of the modern animal rights movement. “Speciesism” was later included in major English dictionaries.

The argument

The argument against speciesism is often presented in the following steps:

1. Morally relevant characteristics, such as the capacity to feel pain and pleasure, are what entitle a being to moral consideration.
2. Many non-human animals possess these characteristics.
3. Species membership itself, like race or sex, is a biological category and not in itself morally relevant.
4. Therefore, giving lesser consideration to the comparable interests of an animal merely because it belongs to a different species is unjustified.

Singer’s version of the argument rests on the principle of equal consideration of interests: comparable interests, such as an interest in avoiding suffering, should be given equal weight regardless of whose interests they are. This does not mean that all beings should be treated identically. A pig has no interest in voting, for example, but has an interest in not suffering.

Supporters often cite the 18th-century philosopher Jeremy Bentham, who wrote: “The question is not, Can they reason? nor, Can they talk? but, Can they suffer?”

Forms of speciesism

Writers on the topic distinguish between several forms, including:

• Anthropocentrism – the view that only human interests matter morally, or that they always outweigh animal interests.
• Selective concern – treating some species, such as dogs and cats, as companions while treating others, such as pigs or chickens, as food. The psychologist Melanie Joy’s concept of carnism addresses this pattern.
• Institutional speciesism – laws and practices that classify animals as property and permit their use in agriculture, research and entertainment, such as in factory farming.

Scientific context

Arguments about speciesism often draw on scientific research into animal sentience. In 2012 a group of neuroscientists signed the Cambridge Declaration on Consciousness, which stated that non-human animals, including all mammals and birds and many other creatures such as octopuses, possess the neurological substrates that generate consciousness. In 2024, the New York Declaration on Animal Consciousness, signed by a group of scientists and philosophers, stated that there is strong scientific support for conscious experience in mammals and birds and at least a realistic possibility of it in all vertebrates and many invertebrates.

Criticism

Speciesism as a concept has been criticised from several directions:

• Some philosophers, such as Carl Cohen, have argued that humans have rights because of capacities typical of the human species, such as moral agency, and that animals do not have rights in the same sense.
• Others, such as Bernard Williams, defended a degree of human partiality as natural and not comparable to racism.
• Critics have objected to the analogy with racism and sexism, arguing that it is inappropriate or offensive. Supporters respond that the analogy concerns the structure of the reasoning, not the comparison of victims.
• The “argument from marginal cases” — that if capacities such as rationality ground moral status, some humans would lack it — is often used by anti-speciesists and remains contested.

Examples of speciesism

Relationship to veganism

Many vegans regard anti-speciesism as a core justification for veganism, since the principle implies that the suffering of farmed animals should be weighed equally with comparable human suffering. Practical expressions include avoiding animal products, supporting animal sanctuaries, and campaigning against practices in the dairy industry and egg industry. Not all critics of speciesism adopt veganism, however, and not all vegans frame their views in these terms.

Frequently asked questions

What is speciesism in simple terms?

It is treating an animal’s interests as less important just because of the species it belongs to, rather than because of any relevant difference between individuals.

Who coined the term speciesism?

The British psychologist Richard D. Ryder, in 1970. The philosopher Peter Singer made it widely known in Animal Liberation (1975).

Is speciesism the same as racism?

Singer and others argue that speciesism has the same structure as racism and sexism: favouring one’s own group on the basis of a morally irrelevant characteristic. Critics reject the comparison, and supporters stress that it concerns the form of the reasoning rather than equating victims.

Does anti-speciesism mean animals and humans must be treated the same?

No. It means comparable interests should be given equal consideration. A pig has no interest in voting, but has an interest in not suffering.

Sources

• Gruen L, Monsó S. The Moral Status of Animals. Stanford Encyclopedia of Philosophy.
• Britannica – Speciesism
• The New York Declaration on Animal Consciousness (2024)
• Singer P. Animal Liberation. New York: New York Review/Random House, 1975.

Last reviewed: 31 October 2026.

See also

• History of Veganism
• Vegan Glossary
• World Vegan Day