Speciesism

The term 'speciesism' first appeared in a 1970 pamphlet by Richard Ryder, who used it to describe the human tendency to favor our own species in moral considerations. Ryder, a psychologist and animal rights advocate, later elaborated the concept in his 1975 book Victims of Science, where he linked it to the use of animals in research.³ Peter Singer adopted the term in Animal Liberation, arguing that speciesism is a form of discrimination that violates the principle of equal consideration of interests. Singer's utilitarian framework holds that the capacity to suffer, not species membership, is the relevant criterion for moral concern.¹ Philosophers have since distinguished between 'human speciesism' (favoring humans) and 'anthropocentric speciesism' (favoring human-like traits), and have debated whether speciesism is always unjustified or only when it is arbitrary.⁴

Critics of speciesism, such as Singer and philosopher Tom Regan, argue that it is morally arbitrary to grant greater weight to human interests simply because we are human. They point to 'marginal cases'—humans with severe cognitive disabilities—who lack the capacities often used to justify human superiority, yet are still afforded moral protection. This 'argument from marginal cases' challenges speciesist assumptions by showing that species membership alone cannot ground moral status.⁵ Defenders, including philosopher Carl Cohen, counter that speciesism is not a prejudice but a necessary basis for moral community, since humans alone possess moral agency and the capacity for reciprocity. Others, like philosopher Bernard Williams, have argued that speciesism is a natural human inclination that does not require justification, though this view remains controversial.⁴

Speciesism has practical implications for how humans treat animals in various domains. In agriculture, speciesist attitudes justify intensive farming practices that cause immense suffering to billions of animals annually, despite evidence that many species experience pain and distress.⁶ In biomedical research, speciesism underlies the use of animals as models for human diseases, a practice that some ethicists argue is inconsistent with the moral status we grant to humans. Conservation policies also reflect speciesist priorities, often favoring charismatic megafauna over less appealing species, a phenomenon known as 'flagship species bias.' The concept has also influenced legal debates, with some countries recognizing animal sentience in legislation, thereby challenging speciesist legal frameworks.²

Speciesism is not limited to human-animal relations; it also appears in debates about artificial intelligence and extraterrestrial life. Some ethicists argue that if AI systems achieve sentience, speciesist logic would wrongly exclude them from moral consideration.⁷ Additionally, the term has been applied to environmental ethics, where 'ecospeciesism' refers to prioritizing entire species over individual animals, a stance that can conflict with animal rights perspectives. Historically, speciesist attitudes have been used to justify colonialism and slavery, as colonizers often viewed indigenous peoples as 'animal-like' to rationalize exploitation.³ The concept has also been critiqued by disability scholars, who argue that the 'marginal cases' argument can inadvertently devalue disabled lives if not carefully framed.⁵

Moral status

The degree of moral consideration an entity is due, often based on capacities like sentience or rationality.

Sentience

The capacity to experience subjective sensations, such as pain or pleasure.

Utilitarianism

An ethical theory that evaluates actions by their consequences, typically maximizing overall well-being.

Marginal cases

Humans with cognitive impairments who lack typical human capacities, used in arguments about animal moral status.