Animal Liberation

Animal Liberation is a 1975 book by the Australian philosopher Peter Singer. Within the animal liberation movement it is widely regarded as the founding philosophical statement of its ideas about animal ethics and suffering. Drawing on the utilitarian tradition, particularly Jeremy Bentham, Singer argues that the interests of animals deserve consideration because they can suffer, and that the notion of rights is not needed to justify that consideration.

The central argument is that the utilitarian principle of seeking the greatest good for the greatest number admits no exception based on species. Singer popularized the term "speciesism", first coined by Richard D. Ryder, to describe discrimination based on species membership, which he likens to discrimination on the basis of skin colour. He contends that intelligence does not justify inferior treatment, since some animals display abilities comparable to those of young children, and some severely intellectually disabled humans have equally limited cognitive capacities. As a practical conclusion he recommends a vegetarian or vegan diet and condemns vivisection, except where medical benefits clearly outweigh the harm to the animals used.

The book went through many editions, and a revised version, Animal Liberation Now, appeared in 2023 with a foreword by Yuval Noah Harari. Activists such as Ingrid Newkirk, co-founder of PETA, and Peter Tatchell have credited the book with changing their behaviour and their view of animals. Singer himself has acknowledged that its impact was more modest than he had hoped. It has also drawn criticism: Roger Scruton judged it lacking in philosophical argument, while Richard Posner and Martha Nussbaum questioned the utilitarian foundations of its theory.