The internationally renowned Australian philosopher Peter Albert David Singer (born 1946) is best known for his book Animal Liberation. However, he also made important contributions in theoretical ethics and in other areas of applied ethics.

Peter Albert David Singer was born on July 6, 1946, in Melbourne, Australia. His parents, Cora and Ernest Singer, had arrived in Australia eight years earlier, fleeing from their native Vienna to escape the persecution of Jews shortly after the Anschluss, the political union of Austria and Germany. By the time Peter was born, his father had become a successful importer of tea and coffee and his mother, already a qualified medical practitioner in Vienna, had cleared all the restrictive barriers then placed in the path of overseas doctors and was once again able to practice her chosen profession.

Keen to integrate their children into Australian society, Cora and Ernest Singer--neither of them religious believers--had decided to send Peter and his sister Joan to prestigious Protestant schools and spoke to them in English only. (It was not until Peter went to high school and university that he finally learned German.) Peter's childhood was comfortable and fairly conventional. He attended Boy Scouts, followed the local football team, went on annual skiing holidays with his family, and did well at school. He went on to study law, history, and philosophy at Melbourne University. It was the study of philosophy that would eventually turn this bright but as yet unremarkable young man into one of the leading and most controversial thinkers of his time.

The story of the radical thinker Singer begins in England in 1970. By that time Singer--now married to Renata, a fellow student from his Melbourne University days--was a graduate student in moral and political philosophy at Oxford University. There he met with other graduate students who abstained from eating meat for purely ethical reasons. Discussions with these vegetarians convinced Singer that it was morally wrong to eat meat; eating animals was, he came to believe, a systematic form of oppression of one species by another. He and Renata became vegetarians themselves.

Five years later, in 1975, Singer published Animal Liberation, the book that challenged traditional thinking about the moral status of nonhuman animals and was to provide the intellectual foundation for the worldwide animal liberation movement. The mistreatment of animals in factory farms and as tools for research, Singer argued, is based on an indefensible prejudice in favor of our own species. In these and other practices, the interests of animals are cruelly disregarded to satisfy our own often trivial interests. This is "speciesism," a prejudice akin to that displayed by the racist who discriminates between people on the basis of such morally irrelevant characteristics as the color of their skin.

Animal Liberation sold more than 400,000 copies, was translated into eight languages, and also led to some important practical changes. It has been described as "the bible" of the animals liberation movement--quite an irony, because Singer himself does not subscribe to any religious views and believes that ethics must be based on reason rather than on religion.

While Singer was best known for his book Animal Liberation, his standing as a first-rate philosopher and critical thinker does not rest on this book alone. His other books include Democracy and Disobedience, The Expanding Circle, The Reproduction Revolution (with Deane Wells), Should the Baby Live (with Helga Kuhse), and How Are We To Live? There are also two brief introductions to Marx and Hegel, as well as numerous anthologies and collections. In a later collection, The Great Ape Project, Singer and his co-editor, Paola Cavalleri, provide evidence that the great apes possess all the morally relevant attributes characteristic of persons and should hence be granted basic human rights.

The best introduction to Singer's work is Practical Ethics, first published in 1979 and revised in 1993. In this book Singer defended a consequentialist and utilitarian approach to ethics. The moral nature of actions, he argued, does not depend on adherence to simple moral rules, such as "Do not lie," but rather on the consequences of those actions. While lying is ordinarily wrong, it is not wrong where the telling of truth would result in great harm.

Singer taught and held appointments at various Australian and overseas universities. Beginning in 1977 he was professor of philosophy at Monash University in Melbourne, Australia, and after 1983, director or deputy director of the Monash University Centre for Human Bioethics.

Singer was not only a philosopher; he was also an activist. If there was something seriously wrong with the world, he wanted to change it. He lobbied governments and interest groups and participated in many demonstrations and protests that highlighted wrongful practices. To demonstrate the plight of battery hens, he sat in oversized cages on city squares, led peaceful marches, and held vigil in front of factory farms and fur shops. He got himself arrested for trespassing when he and some fellow animal liberationists tried to take photos of cruelly confined sows on a piggery partly owned by the prime minister of Australia.

A 1989 Time Australia profile on Singer bore the headline "Saintly or Satanic?" If Singer's fight for animal rights earned him the adjective "saintly," it was his writings in the field of bioethics that led some to think of him as "satanic." Because he believed that species is not a morally relevant boundary and that the like interests of all beings deserve equal moral consideration, Singer consistently condemned cruel treatment of animals while supporting destructive experimentation on early human in vitro embryos. The morally relevant difference, Singer argued, is that animals have interests because they can suffer; early human embryos, on the other hand, are nonsentient beings, cannot suffer, and hence have no interests.

These conclusions sent shock-waves through the Australian and international bioethical community, as did Singer's rejection of the traditional distinction between killing and letting die in the practice of medicine. It is widely believed that it is acceptable to allow a terminally ill patient to die or to refrain from resuscitating a seriously disabled newborn infant. But what, asked Singer, is the moral difference between deliberately allowing a patient to die and helping a patient to die? Is it not sometimes better to take active steps to end a patient's life, particularly if this prevents much unnecessary suffering during the dying process? "Taking active steps" means killing or euthanasia--a practice advocated by Singer under some clearly defined circumstances. Some people find his conclusions so abhorrent that they wish to describe Singer as "satanic." There were even attempts to prevent him from speaking and lecturing in Germany--a country still living in the shadows of the so-called "euthanasia" programs perpetrated under Hitler's Nazi regime.

In his Rethinking Life and Death (1994), Singer provoked more controversy when he elaborated on and amplified many of these conclusions, arguing that, for example, people who no longer have brain function but are not legally dead may have vital organs removed. He argued the ethical propriety of numerous controversial positions on utilitarian grounds and characterized commonly held moral objections to his views as "speciesism." He proposed a radically new ethics based on the quality of life rather than on its sanctity.

In 1998, Singer was awarded with the Ira W. DeCamp Professorship of Bioethics at Princeton University. This decision was met with much criticism due to Singer's views on killing disabled babies. Although controversy surrounded his appointment to the professorship, the University stood by its decision and Singer remained at the University. More that 250 people protested during Singer 's first day of classes at Princeton in September 1999.

Those who knew him well, who were his friends, his colleagues, or his fellow fighters for the rights of animals or the terminally ill, saw Singer as neither saintly nor satanic. They would describe him as a generous and warm-hearted social critic and reformer--and, of course, as one of the outstanding practical philosophers of our time.

Further Reading

• The full text of the Time Australia profile of Peter Singer is in the issue of November 20, 1989. Books by Peter Singer include Democracy and Disobedience (1973); Animal Liberation: A New Ethics for Our Treatment of Animals (1975; second edition 1990); Animal Rights and Human Obligations: An Anthology (co-editor with Thomas Regan, 1976); Practical Ethics (1979; second edition 1993); Marx (1980); Animal Factories (co-author with James Mason, 1980); The Expanding Circle: Ethics and Sociobiology (1981); Hegel (1982); Test-Tube Babies: A Guide to Moral Questions, Present Techniques, and Future Possibilities (co-edited with William Walters, 1982); The Reproduction Revolution: New Ways of Making Babies (co-author with Deane Wells, 1984); Should the Baby Live? The Problem of Handicapped Infants (co-author with Helga Kuhse, 1985); In Defence of Animals (ed., 1985); Ethical and Legal Issues in Guardianship Options for Intellectually Disadvantaged People (co-author with Terry Carney, 1986); Applied Ethics (ed., 1986); Animal Liberation: A Graphic Guide (co-author with Lori Gruen, 1987); Embryo Experimentation (co-editor with Helga Kuhse, Stephen Buckle, Karen Dawson, and Pascal Kasimba, 1990); A Companion to Ethics (ed., 1991); Save the Animals! (Australian edition, co-author with Barbara Dover and Ingrid Newkirk, 1991); The Great Ape Project: Equality Beyond Humanity (co-editor with Paola Cavalieri, 1993); How Are We To Live? Ethics in an Age of Self-Interest (1993); and Rethinking Life and Death (1994).