Peter Albert David Singer AC (born 6 July 1946) is an Australian moral philosopher. He is currently the Ira W. DeCamp Professor of Bioethics at Princeton University, and a Laureate Professor at the Centre for Applied Philosophy and Public Ethics at the University of Melbourne. He specialises in applied ethics and approaches ethical issues from a secular, preference utilitarian perspective. He is known in particular for his book, Animal Liberation (1975), a canonical text in animal rights/liberation theory.
On two occasions Singer served as chair of the philosophy department at Monash University, where he founded its Centre for Human Bioethics. In 1996 he stood unsuccessfully as a Greenscandidate for the Australian Senate. In 2004 he was recognised as the Australian Humanist of the Year by the Council of Australian Humanist Societies, and in June 2012 was named a Companion of the Order of Australia for his services to philosophy and bioethics. He serves on the Advisory Board of Incentives for Global Health, the NGO formed to develop the Health Impact Fund proposal. He was voted one of Australia’s ten most influential public intellectuals in 2006.
Life and career
Singer’s parents were Viennese Jews who emigrated to Australia from Vienna in 1938, after Austria’s annexation by Nazi Germany. They settled in Melbourne, where Singer was born. His grandparents were less fortunate: his paternal grandparents were taken by the Nazis to Łódź, and were never heard from again; his maternal grandfather died in the Theresienstadt concentration camp. He has a sister, Joan (now Joan Dwyer). Singer’s father imported tea and coffee, while his mother practiced medicine. He attended Preshil and later Scotch College. After leaving school, Singer studied law, history and philosophy at the University of Melbourne, gaining his BA degree (hons) in 1967. He received an MA for a thesis entitled Why should I be moral? in 1969. He was awarded a scholarship to study at the University of Oxford, and obtained from there a B.Phil in 1971, with a thesis on civil disobedience supervised by R. M. Hare and subsequently published as a book in 1973. Singer names Hare and Australian philosopher H. D. McCloskey as his two most important mentors.
After spending two years as a Radcliffe lecturer at University College, Oxford, he was a visiting professor at New York University for 16 months. He returned to Melbourne in 1977, where he spent most of his career, aside from appointments as visiting faculty abroad, until his move to Princeton in 1999. In June 2011 it was announced he would join the professoriate of New College of the Humanities, a private college in London, in addition to his work at Princeton.
According to philosopher Helga Kuhse, Singer is “almost certainly the best-known and most widely read of all contemporary philosophers”. Michael Specter wrote that Singer is among the most influential of contemporary philosophers.
Published in 1975, Animal Liberationhas been cited as a formative influence on leaders of the modern animal liberation movement. The central argument of the book is an expansion of the utilitarian idea that “the greatest good of the greatest number” is the only measure of good or ethical behaviour. Singer argues that there is no reason not to apply this to other animals. He popularized the term “speciesism”, which was originally coined by Richard D. Ryder, to describe the practice of privileging humans over other animals.
Singer’s most comprehensive work, Practical Ethics (1979), analyzes in detail why and how living beings’ interests should be weighed. His principle of equal consideration of interests does not dictate equal treatment of all those with interests, since different interests warrant different treatment. All have an interest in avoiding pain, for instance, but relatively few have an interest in cultivating their abilities. Not only does his principle justify different treatment for different interests, but it allows different treatment for the same interest when diminishing marginal utility is a factor. For example, this approach would privilege a starving person’s interest in food over the same interest of someone who is only slightly hungry.
Among the more important human interests are those in avoiding pain, in developing one’s abilities, in satisfying basic needs for food and shelter, in enjoying warm personal relationships, in being free to pursue one’s projects without interference, “and many others”. The fundamental interest that entitles a being to equal consideration is the capacity for “suffering and/or enjoyment or happiness”. Singer holds that a being’s interests should always be weighed according to that being’s concrete properties. He favors a ‘journey’ model of life, which measures the wrongness of taking a life by the degree to which doing so frustrates a life journey’s goals. The journey model is tolerant of some frustrated desire and explains why persons who have embarked on their journeys are not replaceable. Only a personal interest in continuing to live brings the journey model into play. This model also explains the priority that Singer attaches to interests over trivial desires and pleasures.
Singer’s ideas require the concept of an impartial standpoint from which to compare interests. He has wavered about whether the precise aim is the total amount of satisfied interests or the most satisfied interests among those beings who already exist prior to the decision-making. The second edition of Practical Ethics disavows the first edition’s suggestion that the total and prior-existence views should be combined. The second edition asserts that preference-satisfaction utilitarianism, incorporating the ‘journey’ model, applies without invoking the first edition’s suggestion about the total view. The details are fuzzy, however, and Singer admits that he is “not entirely satisfied” with his treatment.
Ethical conduct is justifiable by reasons that go beyond prudence to “something bigger than the individual,” addressing a larger audience. Singer thinks this going-beyond identifies moral reasons as “somehow universal”, specifically in the injunction to ‘love thy neighbor as thyself’, interpreted by him as demanding that one give the same weight to the interests of others as one gives to one’s own interests. This universalising step, which Singer traces from Kant to Hare, is crucial and sets him apart from those moral theorists, from Hobbes to David Gauthier, who tie morality to prudence. Universalisation leads directly to utilitarianism, Singer argues, on the strength of the thought that one’s own interests cannot count for more than the interests of others. Taking these into account, one must weigh them up and adopt the course of action that is most likely to maximise the interests of those affected; utilitarianism has been arrived at. Singer’s universalising step applies to interests without reference to who has them, whereas a Kantian’s applies to the judgments of rational agents (in Kant’s kingdom of ends, or Rawls’s Original Position, etc.). Singer regards Kantian universalisation as unjust to animals. As for the Hobbesians, Singer attempts a response in the final chapter of Practical Ethics, arguing that self-interested reasons support adoption of the moral point of view, such as ‘theparadox of hedonism’, which counsels that happiness is best found by not looking for it, and the need most people feel to relate to something larger than their own concerns.
Practical Ethics includes a chapter arguing for the redistribution of wealth to ameliorate absolute poverty (Chapter 8, “Rich and Poor”), and another making a case for resettlement of refugees on a large scale in industrialised countries (Chapter 9, “Insiders and Outsiders”).
Although the natural, non-sentient environment has no intrinsic value for a utilitarian like Singer, environmental degradation is a profound threat to sentient life, and for this reason he states that environmentalists are right to speak of wilderness as a ‘world heritage’.
Abortion, euthanasia and infanticide
Consistent with his general ethical theory, Singer holds that the right to life is essentially tied to a being’s capacity to hold preferences, which in turn is essentially tied to a being’s capacity to feel pain and pleasure. In his view, the central argument against abortion may be stated as the following syllogism:
It is wrong to kill an innocent human being.
A human fetus is an innocent human being.
Therefore it is wrong to kill a human fetus.
In his book Rethinking Life and Death, as well as in Practical Ethics, Singer asserts that, if we take the premises at face value, the argument is deductively valid. Singer comments that defenders of abortion attack the second premise, suggesting that the fetus becomes a “human” or “alive” at some point after conception; however, Singer finds this argument flawed in that that human development is a gradual process, and it is nearly impossible to mark a particular moment in time as the moment at which human life begins.
Singer at MIT.
Singer’s argument for abortion differs from many other proponents of abortion, then; rather than attacking the second premise of the anti-abortion argument, Singer attacks the first premise, denying that it is necessarily wrong to take innocent human life:
[The argument that a fetus is not alive] is a resort to a convenient fiction that turns an evidently living being into one that legally is not alive. Instead of accepting such fictions, we should recognise that the fact that a being is human, and alive, does not in itself tell us whether it is wrong to take that being’s life.
Singer states that arguments for or against abortion should be based on utilitarian calculation which compares the preferences of a woman against the preferences of the fetus. In his view a preference is anything sought to be obtained or avoided; all forms of benefit or harm caused to a being correspond directly with the satisfaction or frustration of one or more of its preferences. Since a capacity to experience the sensations of suffering or satisfaction is a prerequisite to having any preferences at all, and a fetus, up to around eighteen weeks, says Singer, has no capacity to suffer or feel satisfaction, it is not possible for such a fetus to hold any preferences at all. In a utilitarian calculation, there is nothing to weigh against a woman’s preferences to have an abortion; therefore, abortion is morally permissible.
Similar to his argument for abortion, Singer argues that newborns lack the essential characteristics of personhood—”rationality, autonomy, and self-consciousness”—and therefore “killing a newborn baby is never equivalent to killing a person, that is, a being who wants to go on living.”
Singer classifies euthanasia as voluntary, involuntary, or non-voluntary. Voluntary euthanasia is that to which the subject consents.
Singer’s book Rethinking Life and Death: The Collapse of Our Traditional Ethics offers further examination of the ethical dilemmas concerning the advances of medicine. He covers the value of human life and quality of life ethics in addition to abortion and other controversial ethical questions.
Religious critics have argued that Singer’s ethic ignores and undermines the traditional notion of the sanctity of life. Singer agrees and believes the notion of the sanctity of life ought to be discarded as outdated, unscientific and irrelevant to understanding problems in contemporary bioethics.
Singer has experienced the complexities of some of these questions in his own life. His mother had Alzheimer’s disease. He said, “I think this has made me see how the issues of someone with these kinds of problems are really very difficult”. In an interview with Ronald Bailey, published in December 2000, he explained that his sister shares the responsibility of making decisions about his mother. He did say that, if he were solely responsible, his mother might not continue to live.
In “Famine, Affluence, and Morality”,one of Singer’s best-known philosophical essays, he argues that some people living in abundance while others starve is morally indefensible. Singer proposes that anyone able to help the poor should donate part of their income to aid poverty relief and similar efforts. Singer reasons that, when one is already living comfortably, a further purchase to increase comfort will lack the same moral importance as saving another person’s life. Singer himself reports that he donates 25 percent of his salary to Oxfam and UNICEF.
In “Rich and Poor”, the version of the aforementioned article that appears in the second edition of Practical Ethics, his main argument is presented as follows:
If we can prevent something bad without sacrificing anything of comparable significance, we ought to do it; absolute poverty is bad; there is some poverty we can prevent without sacrificing anything of comparable moral significance; therefore we ought to prevent some absolute poverty.
Singer’s most recent book, The Life You Can Save, makes the argument that it is a clear-cut moral imperative for citizens of developed countries to give more to charitable causes that help the poor. While Singer acknowledges that there are problems with ensuring that money goes where it is most needed and that it is used effectively, he does not think that these practical difficulties undermine his original conclusion (that people should make a much greater effort to reduce poverty).
Doping in elite sports
Singer agrees with Julian Savulescu that elite athletes should be allowed to take whatever performance-enhancing drugs they wish, “as long as it is safe for them to do so.” The argument is that, “without drugs, those with the best genes have an unfair advantage. . . . Setting a maximum level of red blood cells [for endurance events] actually levels the playing field by reducing the impact of the genetic lottery. Effort then becomes more important than having the right genes.”
Evolutionary biology and leftist politics
In A Darwinian Left, Singer outlines a plan for the political left to adapt to the lessons of evolutionary biology. He says that evolutionary psychology suggests that humans naturally tend to be self-interested. He further argues that the evidence that selfish tendencies are natural must not be taken as evidence that selfishness is right. He concludes that game theory (the mathematical study of strategy) and experiments in psychology offer hope that self-interested people will make short-term sacrifices for the good of others, if society provides the right conditions. Essentially Singer claims that although humans possess selfish, competitive tendencies naturally, they have a substantial capacity for cooperation that has also been selected for during human evolution. Singer’s writing in Greater Good magazine, published by the Greater Good Science Center of the University of California, Berkeley, includes the interpretation of scientific research into the roots of compassion, altruism, and peaceful human relationships.
Nonetheless, he claims not to be anti-capitalist. In an interview with New Left Project in 2010, he said the following:
Capitalism is very far from a perfect system, but so far we have yet to find anything that clearly does a better job of meeting human needs than a regulated capitalist economy coupled with a welfare and health care system that meets the basic needs of those who do not thrive in the capitalist economy.
He then adds that “If we ever do find a better system, I’ll be happy to call myself an anti-capitalist.”
Although he has expressed admiration for many of the values promoted by secular humanism, Singer believes it to be incomplete and promotes a preference utilitarian view he calls “personism” instead.
In 1985, Singer wrote a book with the physician Deanne Wells arguing that surrogate motherhood should be allowed and regulated by the state by establishing non-profit ‘State Surrogacy Boards’, which would ensure fairness between surrogate mothers and surrogacy-seeking parents. Singer and Wells endorsed both the payment of medical expenses endured by surrogate mothers and an extra “fair fee” to compensate the surrogate mother.
Vegetarianism and ethics of food consumption
In an article for the online publication China dialogue, Singer called Western-style meat production cruel, unhealthy and damaging to the ecosystem. He rejected the idea that the method was necessary to meet the population’s increasing demand, explaining that animals in factory farms have to eat food grown explicitly for them, and they burn up most of the food’s energy just to breathe and keep their bodies warm.
Singer calls himself a vegetarian and a “flexible vegan”. In his May 2006 interview in Mother Jones, he states:
I don’t eat meat. I’ve been a vegetarian since 1971. I’ve gradually become increasingly vegan. I am largely vegan but I’m a flexible vegan. I don’t go to the supermarket and buy non-vegan stuff for myself. But when I’m traveling or going to other people’s places I will be quite happy to eat vegetarian rather than vegan.
In addition to his addressing issues concerning the consumption of animal products, Singer’s “Can You Do Good by Eating Well?” in Greater Good examines the ethics of eating locally grown food.
In a 2001 review of Midas Dekkers’ Dearest Pet: On Bestiality, Singer argues that sexual activities between humans and animals that result in harm to the animal should remain illegal, but that “sex with animals does not always involve cruelty” and that “mutually satisfying activities” of a sexual nature may sometimes occur between humans and animals, and that writer Otto Soyka would condone such activities. This position is countered by fellow philosopher Tom Regan, who writes that the same argument could be used to justify having sex with children. Regan writes that Singer’s position is a consequence of his adapting a utilitarian, or consequentialist, approach to animal rights, rather than a strictly rights-based one, and argues that the rights-based position distances itself from non-consensual sex. The Humane Society of the United States takes the position that all sexual molestation of animals by humans is abusive, whether it involves physical injury or not.
Commenting on Singer’s article “Heavy Petting,” in which he argues that zoo sexual activity need not be abusive, and that relationships could form which were mutually enjoyed, Ingrid Newkirk, president of the animal rights group PETA, argued that, “If a girl gets sexual pleasure from riding a horse, does the horse suffer? If not, who cares? If you French kiss your dog and he or she thinks it’s great, is it wrong? We believe all exploitation and abuse is wrong. If it isn’t exploitation and abuse, [then] it may not be wrong.” A few years later, Newkirk clarified in a letter to the Canada Free Press that she was strongly opposed to any exploitation of, and all sexual activity with, animals.
Singer believes that although sex between species is not normal or natural, it does not constitute a transgression of our status as human beings, because human beings are animals or, more specifically, “we are great apes”.
Singer lecturing at Oxford University
Criticism of Singer
Singer’s positions have been criticised by groups, such as advocates for disabled people and right-to-life supporters, concerned with what they see as his attacks upon human dignity. Singer has replied that many people judge him based on secondhand summaries and short quotations taken out of context, not his books or articles.
Some claim that Singer’s utilitarian ideas lead to eugenics. American publisher Steve Forbes ceased his donations to Princeton University in 1999 because of Singer’s appointment to a prestigious professorship. Nazi-hunter Simon Wiesenthal wrote to organisers of a Swedish book fair to which Singer was invited that “A professor of morals … who justifies the right to kill handicapped newborns … is in my opinion unacceptable for representation at your level.” Marc Maurer, President of the National Federation of the Blind, criticised Singer’s appointment to the Princeton Faculty in a banquet speech at the organisation’s national convention in July 2001, claiming that Singer’s support for euthanizing disabled babies could lead to disabled older children and adults being valued less as well. Theodore Dalrymple wrote in 2010 that Singerian moral universalism is “preposterous—psychologically, theoretically, and practically”.
Singer’s work has attracted criticism from other philosophers. Bernard Williams, who was a critic of utilitarianism, said of Singer that he “is always so keen to mortify himself and tell everyone how to live”. Williams criticized Singer’s ethic by saying that he’s “always so damn logical” and thus “leaves out an entire dimension of value”. Williams claimed that Singer’s utilitarianism is impractical as it’s impossible to “make these calculations and comparisons in real life”.
In 1989 and 1990, Peter Singer’s work was the subject of a number of protests in Germany. A course in ethics led by Dr Hartmut Kliemt at the University of Duisburg where the main text used was Singer’s Practical Ethics was, according to Singer, “subjected to organized and repeated disruption by protesters objecting to the use of the book on the grounds that in one of its ten chapters it advocates active euthanasia for severely disabled newborn infants”. The protests led to the course being shut down.
When Singer attempted to speak during a lecture at Saarbrücken, he was interrupted by a group of protesters including advocates for the disabled. He offered the protesters the opportunity to explain why he should not be allowed to speak. The protesters indicated that they believed he was opposed to all rights for the disabled. They were unaware that, although Singer believes that some lives are so blighted from the beginning that their parents may decide their lives are not worth living, in other cases, once the decision is made to keep them alive, everything that can be done to improve the quality of their life should, to Singer’s mind, be done. The ensuing discussion revealed that there were many misconceptions about his positions, but the revelation did not end the controversy. One of the protesters expressed that entering serious discussions was a tactical error.
The same year, Peter Singer was invited to speak in Marburg at a European symposium on “Bioengineering, Ethics and Mental Disability.” The invitation was brutally attacked by leading intellectuals and organizations in German media, with an article in Der Spiegel comparing Singer’s positions to Nazism. The symposium was eventually cancelled and Singer’s invitation consequently withdrawn.
A lecture at the Zoological Institute of the University of Zurich was also interrupted by two groups of protesters. The first group was a group of disabled people who staged a brief protest at the beginning of the lecture. They objected to inviting an advocate of euthanasia to speak. At the end of this protest, when Singer attempted to address their concerns, a second group of protesters rose and began chanting “Singer raus! Singer raus!” (“Singer out!”) When Singer attempted to respond, a protester jumped on stage and grabbed his glasses, and the host ended the lecture. The first group of protesters was distressed by this second, more aggressive group. It had not intended to halt the lecture and even had questions to ask Singer. Singer explains “my views are not threatening to anyone, even minimally” and says that some groups play on the anxieties of those who hear only keywords that are understandably worrying (given the constant fears of ever repeating the Holocaust) if taken with any less than the full context of his belief system.
In 1991, Singer was due to speak along with R. M. Hare and Georg Meggle at the fifteenth International Wittgenstein Symposium in Kirchberg, Austria. Singer has stated that threats were made to Adolf Hübner, then the president of the Austrian Ludwig Wittgenstein Society, that the conference would be disrupted if Singer and Meggle were given a platform. Hübner proposed to the board of the society that Singer’s invitation (as well as the invitations of a number of other speakers) be withdrawn. The Society decided to cancel the symposium.
In an article originally published in The New York Review of Books, Singer argued that the protests dramatically increased the amount of coverage he got: “instead of a few hundred people hearing views at lectures in Marburg and Dortmund, several millions read about them or listened to them on television”. Despite this, Singer argues that it has led to a difficult intellectual climate, with professors not able to teach courses in Germany on applied ethics and campaigns demanding the resignation of professors who invited Singer to speak.
Meta-ethics and foundational issues
Singer lecturing at Washington University in St. Louis.
Though Singer focuses more than many philosophers on applied ethical questions, he has also written in depth on foundational issues in meta-ethics, including why one ethical system should be chosen over others. In The Expanding Circle, he argues that the evolution of human society provides support for the utilitarian point of view. On his account, ethical reasoning has existed from the time primitive foraging bands had to cooperate, compromise, and make group decisions to survive. He elaborates: “In a dispute between members of a cohesive group of reasoning beings, the demand for a reason is a demand for a justification that can be accepted by the group as a whole.” Thus, consideration of others’ interests has long been a necessary part of the human experience. Singer believes that contemplative analysis may now guide one to accept a broader utilitarianism:
If I have seen that from an ethical point of view I am just one person among the many in my society, and my interests are no more important, from the point of view of the whole, than the similar interests of others within my society, I am ready to see that, from a still larger point of view, my society is just one among other societies, and the interests of members of my society are no more important, from that larger perspective, than the similar interests of members of other societies… Taking the impartial element in ethical reasoning to its logical conclusion means, first, accepting that we ought to have equal concern for all human beings.
Singer elaborates that viewing oneself as equal to others in one’s society and at the same time viewing one’s society as fundamentally superior to other societies may cause an uncomfortablecognitive dissonance. This is the sense in which he means that reason may push people to accept a broader utilitarian stance. Critics like Ken Binmore say that this cognitive dissonance is apparently not very strong, since people often knowingly ignore the interests of faraway societies quite similar to their own, and that the “ought” above only applies if one already accepts Singer’s basic premises about the equality of various interests.
An alternative line taken by Singer about the need for ethics is that living the ethical life may be, on the whole, more satisfying than seeking only material gain. He invokes the hedonistic paradox, noting that those who pursue material gain seldom find the happiness they seek. Having a broader purpose in life may lead to more long-term happiness. On this account, impartial (self-sacrificing) behavior in particular matters may be motivated by self-interested considerations from a broader perspective.
Singer has also implicitly argued that an airtight defense of utilitarianism is not crucial to his work. In “Famine, Affluence, and Morality”,he begins by saying that he would like to see how far a seemingly innocuous and widely endorsed principle can take us; the principle is that one is morally required to forgo a small pleasure to relieve someone else’s immense pain. He then argues that this principle entails radical conclusions—for example, that affluent people are very immoral if they do not give up some luxury goods to donate the money for famine relief. If his reasoning is valid, he goes on to argue, either it is not very immoral to value small luxuries over saving many lives, or such affluent people are very immoral. As Singer argues in the same essay, regardless of the soundness of his fundamental defense of utilitarianism, his argument has value in that it exposes conflicts between many people’s stated beliefs and their actions.
On 11 June 2012, Singer was named an Companion of the Order of Australia for “eminent service to philosophy and bioethics as a leader of public debate and communicator of ideas in the areas of global poverty, animal welfare and the human condition.”
Singer is one of the most prolific writers in philosophy, sometimes publishing several books a year as well as public engagement. His books include:
Animal Liberation: A New Ethics for our Treatment of Animals, New York Review/Random House, New York, 1975; Cape, London, 1976; Avon, New York, 1977; Paladin, London, 1977; Thorsons, London, 1983. Harper Perennial Modern Classics, New York, 2009.
Democracy and Disobedience, Clarendon Press, Oxford, 1973; Oxford University Press, New York, 1974; Gregg Revivals, Aldershot, Hampshire, 1994
Animal Rights and Human Obligations: An Anthology (co-editor with Thomas Regan), Prentice-Hall, New Jersey, 1976. 2nd revised edition, Prentice-Hall, New Jersey, 1989
Practical Ethics, Cambridge University Press, Cambridge, 1979; second edition, 1993; third edition, 2011 Marx, Oxford University Press, Oxford, 1980; Hill & Wang, New York, 1980; reissued as Marx: A Very Short Introduction, Oxford University Press, 2000; also included in full in K. Thomas (ed.), Great Political Thinkers: Machiavelli, Hobbes, Mill and Marx, Oxford University Press, Oxford, 1992
Animal Factories (co-author with James Mason), Crown, New York, 1980
The Expanding Circle: Ethics and Sociobiology, Farrar, Straus and Giroux, New York, 1981; Oxford University Press, Oxford, 1981; New American Library, New York, 1982.
Hegel, Oxford University Press, Oxford and New York, 1982; reissued as Hegel: A Very Short Introduction, Oxford University Press, 2001; also included in full in German Philosophers: Kant, Hegel, Schopenhauer, Nietzsche, Oxford University Press, Oxford, 1997
Test-Tube Babies: a guide to moral questions, present techniques, and future possibilities (co-edited with William Walters), Oxford University Press, Melbourne, 1982
The Reproduction Revolution: New Ways of Making Babies (co-author with Deane Wells), Oxford University Press, Oxford, 1984. revised American edition, Making Babies, Scribner’s New York, 1985
Should the Baby Live? The Problem of Handicapped Infants (co-author with Helga Kuhse), Oxford University Press, Oxford, 1985; Oxford University Press, New York, 1986; Gregg Revivals, Aldershot, Hampshire, 1994.
In Defence of Animals (ed.), Blackwells, Oxford, 1985; Harper & Row, New York, 1986.
Ethical and Legal Issues in Guardianship Options for Intellectually Disadvantaged People (co-author with Terry Carney), Human Rights Commission Monograph Series, no. 2, Australian Government Publishing Service, Canberra, 1986
Applied Ethics (ed.), Oxford University Press, Oxford, 1986
Animal Liberation: A Graphic Guide (co-author with Lori Gruen), Camden Press, London, 1987
Embryo Experimentation (co-editor with Helga Kuhse, Stephen Buckle, Karen Dawson and Pascal Kasimba), Cambridge University Press, Cambridge, 1990; paperback edition, updated, 1993
A Companion to Ethics (ed.), Basil Blackwell, Oxford, 1991; paperback edition, 1993
Save the Animals! (Australian edition, co-author with Barbara Dover and Ingrid Newkirk), Collins Angus & Robertson, North Ryde, NSW, 1991
The Great Ape Project: Equality Beyond Humanity (co-editor with Paola Cavalieri), Fourth Estate, London, 1993; hardback, St Martin’s Press, New York, 1994; paperback, St Martin’s Press, New York, 1995
How Are We to Live? Ethics in an Age of Self-interest, Text Publishing, Melbourne, 1993; Mandarin, London, 1995; Prometheus, Buffalo, NY, 1995; Oxford University Press, Oxford, 1997
Ethics (ed.), Oxford University Press, Oxford, 1994
Individuals, Humans and Persons: Questions of Life and Death (co-author with Helga Kuhse), Academia Verlag, Sankt Augustin, Germany, 1994
Rethinking Life and Death: The Collapse of Our Traditional Ethics, Text Publishing, Melbourne, 1994; St Martin’s Press, New York, 1995; reprint 2008. Oxford University Press, Oxford, 1995
The Greens (co-author with Bob Brown), Text Publishing, Melbourne, 1996
The Allocation of Health Care Resources: An Ethical Evaluation of the “QALY” Approach (co-author with John McKie, Jeff Richardson and Helga Kuhse), Ashgate/Dartmouth, Aldershot, 1998
A Companion to Bioethics (co-editor with Helga Kuhse), Blackwell, Oxford, 1998
Ethics into Action: Henry Spira and the Animal Rights Movement, Rowman and Littlefield, Lanham, Maryland, 1998; Melbourne University Press, Melbourne, 1999
Bioethics. An Anthology (co-editor with Helga Kuhse), Blackwell, 1999/ Oxford, 2006
A Darwinian Left, Weidenfeld and Nicolson, London, 1999; Yale University Press, New Haven, 2000.
Writings on an Ethical Life, Ecco, New York, 2000; Fourth Estate, London, 2001.
Unsanctifying Human Life: Essays on Ethics (edited by Helga Kuhse), Blackwell, Oxford, 2001
One World: The Ethics of Globalisation, Yale University Press, New Haven, 2002; Text Publishing, Melbourne, 2002; 2nd edition, pb, Yale University Press, 2004; Oxford Longman, Hyderabad, 2004.
Pushing Time Away: My Grandfather and the Tragedy of Jewish Vienna, Ecco Press, New York, 2003; HarperCollins Australia, Melbourne, 2003; Granta, London, 2004
The President of Good and Evil: The Ethics of George W. Bush, Dutton, New York, 2004; Granta, London, 2004; Text, Melbourne, 2004. How Ethical is Australia? An Examination of Australia’s Record as a Global Citizen (with Tom Gregg), Black Inc, Melbourne, 2004
The Moral of the Story: An Anthology of Ethics Through Literature (co-edited with Renata Singer), Blackwell, Oxford, 2005
In Defense of Animals. The Second Wave (ed.), Blackwell, Oxford, 2005
The Ethics of What We Eat: Why Our Food Choices Matter, Rodale, New York, 2006 (co-author with Jim Mason); Text, Melbourne; Random House, London. Audio version: Playaway
Eating (co-authored with Jim Mason), Arrow, London, 2006
Stem Cell Research: the ethical issues. (co-edited by Lori Gruen, Laura Grabel, and Peter Singer). New York: Blackwells. 2007.
The Bioethics Reader: Editors’ Choice. (co-editor with Ruth Chadwick, Helga Kuhse, Willem Landman and Udo Schüklenk). New York: Blackwells. 2007.
The Future of Animal Farming: Renewing the Ancient Contract (with Marian Stamp Dawkins, and Roland Bonney) 2008. New York: Wiley-Blackwell.
The Life You Can Save: Acting Now to End World Poverty. New York: Random House 2009. (see also thelifeyoucansave.com)
Schaler, Jeffrey A. (Editor.). 2009. Peter Singer Under Fire: The Moral Iconoclast Faces His Critics. Chicago: Open Court Publishers.
Leist A. and P.Singer. (eds.) 2010. J. M. Coetzee and Ethics: Philosophical Perspectives on Literature. New York: Columbia University Press.