Practical Ethics
Practical Ethics is Peter Singer’s influential systematic exposition of how a broadly utilitarian, preference-satisfaction ethics should guide real-world moral decisions. Starting from the question of whether ethics can be objective, Singer develops a consequentialist framework grounded in the principle of equal consideration of interests and then applies it to controversial issues including treatment of animals, abortion and infanticide, euthanasia, global poverty, environmental protection, and obligations toward future generations. The work aims to show that consistent, impartial reasoning requires radical revisions of common moral intuitions and everyday practices.
At a Glance
- Author
- Peter Singer
- Composed
- mid-1970s (first edition), extensively revised 1990s–2000s
- Language
- English
- Status
- original survives
- •The principle of equal consideration of interests: morally similar interests of all sentient beings—human or non-human—must be weighted equally, and any differential treatment requires independent justification rather than mere species membership.
- •Speciesism as a prejudice: giving lesser moral weight to the suffering and interests of non-human animals solely because they are not human is structurally analogous to racism or sexism and is therefore irrational and morally indefensible.
- •Personhood and the wrongness of killing: what makes killing wrong is not simply being biologically human but possessing characteristics of personhood (such as self-consciousness, future-oriented preferences, and a sense of oneself over time); this distinction has implications for abortion, infanticide, and euthanasia.
- •Positive duties to alleviate global poverty: affluent individuals in rich countries are morally obliged to give up substantial resources to prevent suffering and death from poverty-related causes when they can do so at comparatively small moral cost, following a principle akin to the obligation to save a drowning child in a shallow pond.
- •Impartiality and expanding the moral circle: ethical reasoning requires that one transcend personal and local partialities, extending concern to distant strangers, non-human animals, and future generations through consistent application of universalizable principles.
Practical Ethics is one of the most influential works in late twentieth- and early twenty-first-century applied moral philosophy. It helped to establish applied ethics—especially animal ethics, bioethics, and global justice—as central subfields in Anglo-American philosophy and beyond. The book significantly shaped public discourse on animal welfare, vegetarianism and veganism, euthanasia legislation, charitable giving, and environmental responsibility. Its clear exposition of preference utilitarianism and equal consideration of interests has served as a major reference point for both supporters and critics of consequentialist ethics.
1. Introduction
Practical Ethics is a systematic treatise in applied moral philosophy that sets out, develops, and applies a broadly utilitarian framework to a series of concrete moral problems. First published in 1979 and substantially revised in later editions, it is structured to move from abstract questions about the nature of ethics to detailed analysis of controversial topics such as animal treatment, abortion, euthanasia, global poverty, and environmental protection.
The work’s central organizing idea is the principle of equal consideration of interests: comparable interests of all affected beings should receive the same moral weight, regardless of species, nationality, proximity, or personal relationship. This principle is embedded within a version of preference utilitarianism, according to which actions are to be assessed by how far they satisfy the informed and reflective preferences of those affected. Throughout the book, Singer uses this framework to challenge widely held moral intuitions and social practices.
The text is often described as both a philosophical argument and a pedagogical tool. It aims to show how abstract ethical reasoning can have radical implications for individual conduct and public policy, while also modeling a method of argument that proceeds from relatively uncontroversial premises (such as consistency and impartiality) to more contentious conclusions.
In the broader landscape of moral philosophy, Practical Ethics occupies a distinctive place as a clear, unified exposition of consequentialist applied ethics. It is frequently used as a course text and as a focal point in debates over animal ethics, bioethics, and global justice. Supporters regard it as a powerful demonstration of the reach of moral reasoning; critics view it as an illustration of the tensions and costs of a demanding, impartial ethics. The entry’s subsequent sections unpack its background, arguments, controversies, and long-term impact.
2. Historical and Intellectual Context
Practical Ethics emerged in the mid-1970s within a rapidly changing ethical landscape. In Anglo-American philosophy, a long period dominated by meta-ethics and linguistic analysis was giving way to renewed interest in applied ethics, particularly in medicine, politics, and environmental issues. Developments such as advances in life-support technologies, debates over abortion and brain death, and public concern about pollution and population growth created demand for systematic ethical analysis of practical questions.
Singer’s work is strongly shaped by the utilitarian tradition, especially Jeremy Bentham’s and John Stuart Mill’s insistence on impartial concern for all sentient beings. At the same time, he writes against a mid–20th‑century background in which many philosophers emphasized moral emotivism or prescriptivism and were skeptical about substantive ethical argument. His teacher R. M. Hare’s universal prescriptivism, with its focus on consistency and universalizability, is an important influence on Singer’s method and conception of impartiality.
The book also reflects and contributes to the rise of animal ethics as a serious philosophical field. Earlier works, including those of Henry Salt and, contemporaneously, Tom Regan, had argued for the moral relevance of animals, but Singer’s notion of speciesism gave a rhetorically powerful and analytically sharp label to bias in favor of humans.
In global and political terms, the 1970s context of post-colonial development, famine in regions such as Bangladesh, and debates about foreign aid and global inequality informs Singer’s analysis of poverty and international obligation. Environmental concerns, particularly about population, resource depletion, and climate change, also loom in the background, shaping the later chapters and later editions.
Overall, Practical Ethics occupies the intersection of several emerging domains—bioethics, animal ethics, environmental ethics, and global justice—at a moment when philosophy was increasingly expected to address concrete social problems using rigorous argument.
3. Author and Composition
Peter Singer (b. 1946) is an Australian moral philosopher whose work focuses on utilitarian ethics and its application to practical issues. Educated at the University of Melbourne and the University of Oxford, he was strongly influenced by R. M. Hare’s universal prescriptivism and by the classical utilitarian canon. Before Practical Ethics, Singer became widely known in academic and activist circles through his 1975 book Animal Liberation, which framed intensive animal agriculture and experimentation as morally comparable to familiar forms of discrimination.
The composition of Practical Ethics took place in the mid‑1970s while Singer was teaching and writing on applied moral questions. The initial 1979 edition brought together and systematized arguments he had been developing in articles and lectures on animal ethics, famine relief, and euthanasia. It was conceived as a clear, unified introduction to applied ethics for students and non-specialists, but it also advanced a distinct, preference-utilitarian program.
Later editions substantially reworked the original text. The second edition (1993) updated empirical material, expanded discussions of bioethics and disability, and responded implicitly to early criticisms, particularly from disability-rights and deontological perspectives. The third edition (2011) incorporated extensive new material on climate change, globalization, and the then-emerging effective altruism movement, and revised earlier chapters in light of ongoing debates in animal ethics, population ethics, and global justice.
A rough timeline of composition and revision is:
| Date | Event |
|---|---|
| Early–mid 1970s | Singer develops core arguments on animals, famine, and euthanasia |
| 1979 | First edition of Practical Ethics published (Cambridge University Press) |
| 1993 | Second edition with significant revisions and new chapters |
| 2011 | Third edition adding climate change, updated global poverty discussion, and other material |
Across these iterations, Singer maintains a consistent basic framework—equal consideration of interests within a broadly utilitarian structure—while adjusting applications, examples, and some formulations in response to empirical developments and philosophical criticism.
4. Structure and Organization of the Work
Practical Ethics is organized to move from foundational questions about ethics to applied issues, with each part building conceptually on what precedes it. The overall structure can be summarized as follows:
| Part / Chapter Group | Main Focus | Function in the Book |
|---|---|---|
| Part 1: “About Ethics” | Nature of ethics, objectivity, reasons | Establishes that moral judgments aim at truth and must be supported by reasons |
| Part 2: “Equality and Its Implications” | Principle of equality, impartiality | Introduces equal consideration of interests and universalizability |
| Part 3: “Equality for Animals?” | Speciesism, animal suffering | Applies equality to non-human animals and critiques species-based bias |
| Part 4: “What’s Wrong with Killing?” | Personhood, wrongness of killing | Analyzes why killing is wrong and distinguishes biological humanity from personhood |
| Parts 5 & 6: “Taking Life: Humans / Animals” | Bioethical and animal-life questions | Applies prior analysis of killing to abortion, euthanasia, and animal use |
| Part 7: “Rich and Poor” | Global poverty and aid | Extends impartial ethics to economic inequality and charity |
| Part 8: “Insiders and Outsiders” | Partiality and political boundaries | Examines family, national, and cultural loyalties within an impartial framework |
| Part 9: “Climate Change and the Environment” | Environment and future people | Explores duties to the environment and future generations |
| Part 10: “Why Act Morally?” | Motivation and reason | Addresses why one should comply with demanding moral requirements |
Within each part, Singer typically proceeds by: (1) setting out common beliefs or conventional wisdom, (2) articulating a general principle derived from his earlier chapters (e.g., equal consideration of interests), and (3) testing everyday practices against that principle using thought experiments and empirical data.
The organization is deliberately cumulative. For instance, the discussion of global poverty in “Rich and Poor” presupposes the impartiality and universalizability defended in “About Ethics” and “Equality and Its Implications.” Similarly, the bioethical chapters assume the analysis of personhood and killing developed in “What’s Wrong with Killing?”. This structure allows Singer to claim that controversial conclusions about animals, abortion, or aid follow not from ad hoc assumptions, but from a single, consistently applied ethical framework introduced at the outset.
5. Ethical Method and Moral Objectivity
The early chapters of Practical Ethics articulate an ethical method that aims to be rational, impartial, and publicly justifiable. Singer argues that moral judgments are not mere expressions of emotion or preference, but purport to be supported by reasons that others, in principle, could accept. He aligns himself with the view that ethics has an objective dimension: while empirical claims and value claims are distinct, it is still meaningful to say that some moral judgments are better justified than others.
A key methodological tool is universalizability. When a person makes a moral judgment, Singer suggests, they implicitly commit to making the same judgment in all relevantly similar cases. This requirement to treat like cases alike leads, he argues, to a standpoint of impartiality: differences in race, sex, species, or distance cannot justify different treatment unless some further relevant difference is shown.
Singer’s preferred substantive framework is preference utilitarianism. On this view, moral reasoning proceeds by:
- Identifying all the beings affected by an action.
- Determining, as far as possible, their informed, considered preferences.
- Weighing these preferences equally, without arbitrary discounting.
- Choosing the action that best satisfies the total set of preferences.
He contrasts this with classical (hedonistic) utilitarianism, which focuses on pleasure and pain, but treats both as compatible with the same basic method of impartial aggregation.
Critics have questioned whether this method truly supports objectivity. Some deontologists claim that universalizability alone cannot yield substantive duties without presupposing additional moral norms; virtue ethicists suggest that character and context are underplayed. Others challenge whether preference satisfaction is an adequate measure of what is good, especially given adaptive or misinformed preferences.
Singer acknowledges such challenges but maintains that the combination of universalizability, impartiality, and consequential evaluation offers a coherent procedure for reasoning about ethics. Throughout the book he applies this method to concrete issues, using thought experiments and real-world data to test and refine judgments rather than relying solely on moral intuitions.
6. Equality, Speciesism, and Animal Ethics
In the sections on equality and animals, Practical Ethics develops a distinctive approach to moral equality and extends it beyond the human species. Singer distinguishes between factual equality (which clearly does not hold—humans and animals differ in many capacities) and moral equality, understood as the principle that like interests deserve equal consideration.
The Principle of Equal Consideration
Singer formulates equality as a demand on how interests are weighed, not as a claim that all beings are the same. If a pig and a human both have an interest in avoiding intense pain, that interest, he argues, should count equally in moral calculation, unless some further morally relevant difference is shown. Proponents view this as a natural extension of anti-racist and anti-sexist commitments.
Speciesism
To criticize privileging human interests purely because they are human, Singer introduces speciesism:
“If possessing a higher degree of intelligence does not entitle one human to use another for his or her own ends, how can it entitle humans to exploit
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title = {practical-ethics},
author = {Philopedia},
year = {2025},
url = {https://philopedia.com/works/practical-ethics/},
urldate = {December 10, 2025}
}Study Guide
intermediateThe work is written for non-specialists and uses clear language, but it assumes comfort with abstract reasoning and engages with complex, emotionally charged topics (e.g., infanticide, euthanasia, disability, climate ethics). Students familiar with basic ethical theories will find it challenging but accessible.
Practical ethics
The branch of moral philosophy concerned with applying ethical theories and principles to concrete, real-world issues such as euthanasia, poverty, and animal treatment.
Preference utilitarianism
Singer’s favored version of utilitarianism, which evaluates actions by how well they satisfy the informed, considered preferences of all affected beings rather than by producing pleasure alone.
Equal consideration of interests
The principle that like interests of all those affected by an action must be given the same moral weight, regardless of species, race, sex, or other arbitrary distinctions.
Speciesism
A prejudice or bias in favor of the interests of one’s own species against those of other species, which Singer argues is morally analogous to racism and sexism.
Person (Singer’s sense)
A being with self-consciousness, a sense of itself as existing over time, and the capacity for future-directed preferences, which grounds a higher moral status than mere biological humanity.
Sanctity of life doctrine
The view, often religiously grounded, that human life has an inviolable value simply by virtue of being human, a position Singer criticizes as insufficiently sensitive to quality of life and personhood.
Drowning child analogy
Singer’s thought experiment in which failing to save a child drowning in a shallow pond is likened to failing to donate to effective charity, used to argue for strong duties to aid the global poor.
Moral circle and impartiality
The moral circle is the range of beings regarded as deserving moral consideration; impartiality is the requirement that comparable interests receive equal concern, unaffected by arbitrary biases like proximity or species.
How does Singer’s principle of equal consideration of interests differ from the claim that all beings are equal in their capacities or rights, and why does this distinction matter for his arguments about animals?
In what ways is speciesism, as Singer defines it, analogous to racism or sexism, and are there any morally relevant differences that could justify privileging human interests?
Does Singer’s notion of personhood—focused on self-consciousness and future-directed preferences—provide a convincing basis for distinguishing the wrongness of killing infants, adults, and non-human animals?
How does the drowning child analogy aim to show that common attitudes toward charity are morally inconsistent, and what possible objections can be raised against extending the analogy to global poverty?
Is Singer’s form of practical ethics too demanding to be a plausible guide to how we ought to live, especially regarding global poverty and climate change?
To what extent should impartiality override special obligations to family, friends, or compatriots in Singer’s framework?
How has Practical Ethics influenced contemporary debates in animal ethics, bioethics, and effective altruism, and why has it also provoked such intense criticism, especially from disability-rights advocates?