Peter Singer

Peter Singer (born 6 July 1946, Melbourne) is an Australian moral philosopher best known for Animal Liberation (1975), the book widely credited with launching the modern animal rights movement, and for his work on global poverty, bioethics, and effective altruism.

Career

Singer read philosophy at the University of Melbourne and took a BPhil at University College, Oxford, where a conversation with Canadian graduate student Richard Keshen over a lunch tray of meat first turned him toward the question of animals. He returned to Melbourne’s Monash University in 1977, where he spent most of his Australian career, and from 1999 to 2023 held the Ira W. DeCamp Chair in Bioethics at Princeton’s University Center for Human Values. He is now professor emeritus at both institutions.

Key ideas

Animal Liberation argued that the capacity to suffer, not species membership, is what grants a being moral consideration — and that industrial animal agriculture and most laboratory research fail that test. Singer popularized Richard Ryder’s term speciesism to name the prejudice he was attacking. His framework is preference-utilitarian: actions are judged by how well they satisfy the preferences of all affected beings, weighted equally.

Practical Ethics (Cambridge University Press, 1979; 3rd ed. 2011) extended the analysis to abortion, euthanasia, disability, and global poverty. His 1972 essay “Famine, Affluence, and Morality” and the later The Life You Can Save (2009) argue that affluent people are obligated to give significantly to effective charities — a cornerstone of the effective-altruism movement Singer helped shape. In 2009 he founded the charity-evaluation nonprofit of the same name.

Legacy

Animal Liberation has sold more than a million copies and been translated into over twenty languages. Singer rewrote it from scratch as Animal Liberation Now in 2023, updating the science and adding chapters on climate and pandemic risk from animal agriculture. His arguments remain contested — particularly his positions on disability and infanticide — but they shaped a generation of philosophers, activists, and vegans. For the book, see Animal Liberation (1975); for the concept, see Speciesism.