Speciesism

Speciesism is the assignment of different moral status to beings on the basis of their species membership — analogous, in structure, to racism or sexism. The term was popularized by psychologist Richard Ryder in 1970 and made philosophically central by Peter Singer’s Animal Liberation (1975).

The argument in one sentence

If sentience — the capacity to suffer and to have experiences that matter to the one having them — is what gives a being moral weight, then denying that weight on the basis of species is arbitrary: species is not itself a morally relevant property.

Why it matters

Nearly every system of animal use — factory farming, fur, lab experimentation, the exotic pet trade — is defended (implicitly) by the premise that human interests, no matter how trivial, outweigh animal interests, no matter how severe. Naming this premise speciesism is the first step toward examining it.

Common objections

• “But humans are more intelligent.” Intelligence is a gradient, and we do not treat less-intelligent humans as mere commodities. Sentience, not IQ, is the relevant trait.
• “Nature is cruel.” True, but the naturalistic fallacy: what happens in nature does not license what we choose to build.
• “We need animals for food.” Contemporary nutrition science does not support this claim for the vast majority of adults. See Plant-based diet.