Introduction to Utilitarianism

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“The task of the benevolent is surely to diligently seek to promote the benefit of the world and eliminate harm to the world and to take this as a model throughout the world. Does it benefit people? Then do it. Does it not benefit people? Then stop.”


What, morally, ought we to do? Utilitarianism gives an answer: we ought always to promote overall well-being. Compared to other ethical theories, utilitarianism is less deferential to ordinary thought and may tell us to make substantial changes to how we lead our lives. Perhaps more so than any other ethical theory, it has produced a fierce philosophical debate between its proponents and its critics.

Why Do We Need Moral Theories?

When we make moral judgments in everyday life, we often rely on our intuition. If you ask yourself whether or not it’s wrong to eat meat, or to lie to a friend, or to buy sweatshop goods, you probably have a strong gut moral view on the topic. But there are problems with relying merely on our moral intuition.

Historically, people held beliefs we now consider morally horrific. In Western societies, it was once firmly believed to be intuitively obvious that people of color and women have fewer rights than white men; that homosexuality is wrong; and that it was permissible to own slaves. We now see these moral intuitions as badly misguided. This historical track record gives us reason to be concerned that we, in the modern era, may also be unknowingly responsible for serious, large-scale wrongdoing. It would be a very lucky coincidence if the present generation were the first generation whose intuitions were perfectly morally correct.2

Also, people have conflicting moral intuitions, and we need a way to resolve these disagreements. We see the project of moral philosophy as being to reflect on our competing moral intuitions and develop a theory that will tell us what we ought to do, and why. This will then allow us to identify which moral judgments of today are misguided, enabling us to make moral progress and act more ethically.

One of the most prominent and influential attempts to create such a theory is utilitarianism. Utilitarianism was developed by the philosophers Jeremy Bentham and John Stuart Mill, who drew on ideas going back to the ancient Greeks. Utilitarianism has since been widely discussed, and has had significant influence in economics and public policy.

Track Record

While history cannot directly tell us which moral theory is correct, utilitarian moral reasoning has a strong track record of contributing to humanity’s collective moral progress—suggesting that there may at least be something morally salutary to these ideas. The classical utilitarians of the 18th and 19th centuries had many social and political attitudes that were far ahead of their time: As a progressive social reformer, Jeremy Bentham advocated for the separation of church and state; the abolition of slavery and of capital punishment; legal regulations to protect criminals and non-human animals from cruel treatment;3 and the decriminalization of homosexuality.4 Indeed, his manuscripts on homosexuality were so liberal that his editor hid them from the public after Bentham’s death. They were only published two centuries later.

John Stuart Mill defended the provision of social welfare for the poor and of freedom of speech. He was the second MP in the UK Parliament to call for women’s suffrage5 and advocated for gender equality more generally. In his essay The Subjection of Women,6 Mill argued that

the principle which regulates the existing social relations between the two sexes—the legal subordination of one sex to the other—is wrong itself, and now one of the chief hindrances to human improvement; and that it ought to be replaced by a principle of perfect equality, admitting no power or privilege on the one side, nor disability on the other.7

In a similar vein, Henry Sidgwick advocated for women’s education and the freedom of education from religious doctrines. Modern utilitarians like Peter Singer are outspoken advocates against pressing moral problems such as extreme poverty and factory farming.8

The early proponents of utilitarianism were still far from getting everything right. (For example, Mill disappointingly shared the unsavory colonialist attitudes common among his compatriots.) But their utilitarian reasoning led them to escape many of the moral prejudices of their time and reach more enlightened moral and political positions. Those of us living today are, of course, still fallible, just as our forebears were. To help overcome our own biases, our moral and political views may similarly benefit from being checked against utilitarian principles.

What Is Utilitarianism?

We can define utilitarianism in simple terms:

Utilitarianism is the view that one ought always to promote overall well-being.

The core idea is that we should want all lives to go as well as possible,9 with no-one’s well-being counting for more or less than anyone else’s.

Sometimes philosophers talk about “welfare” or “utility” rather than “well-being”, but these words are typically used to mean the same thing.10 (Others sometimes use “well-being” and “happiness” interchangeably, though we’ll take “happiness” to be a narrower concept.)11 Utilitarianism is most commonly applied to evaluate the rightness of actions, but the theory can also evaluate other things, like rules, policies, motives, virtues, and social institutions. It is perhaps unfortunate that the clinical-sounding term “utilitarianism” caught on as a name, especially since in common speech the word “utilitarian” is easily confused with joyless functionality or even outright selfishness.

All ethical theories in the utilitarian family share four defining elements: consequentialism, welfarism, impartiality, and aggregationism, which we’ll define as follows:

  1. Consequentialism: one ought always to promote overall value.
  2. Welfarism: the value of an outcome is wholly determined by the well-being of the individuals in it.
  3. Impartiality: a given quantity of well-being is equally valuable no matter whose well-being it is.
  4. Aggregationism: the value of an outcome is given by the sum value of the lives it contains.12

Utilitarianism’s rivals are theories that deny one or more of the above four elements. For example, they might hold that actions can be inherently right or wrong regardless of their consequences, or that things other than well-being can contribute to an outcome’s value, or that morality allows us to be partial towards our friends and families, or that we should do whatever will most benefit the worst-off member of society.


We cover the four elements of utilitarianism in greater depth, along with further theoretical distinctions, in Chapter 2: Elements and Types of Utilitarianism.

Chapter 3 explains reflective equilibrium as a moral methodology, and presents several arguments for utilitarianism (and similar consequentialist views) over competing approaches to ethics. This includes discussion of the veil of ignorance, the expanding moral circle, and the argument that utilitarianism offers an especially compelling account of what fundamentally matters. This chapter also explains the paradox of deontology, evolutionary debunking arguments, and other objections to non-consequentialist ethics.

Specific theories of well-being and of population ethics are explored in Chapters 4 and 5, respectively. While utilitarianism is often associated with hedonism about well-being and the total view of population ethics (a combination known as classical utilitarianism), other options are also worth considering. It’s especially worth bearing in mind that objections to hedonism or to the total view may yet leave other forms of utilitarianism untouched. (Note that the chapter on population ethics is the most difficult and technical of the book, and some readers may prefer to skip it.)

Chapter 6 and our supplemental article Acting on Utilitarianism explore the practical applications of utilitarianism, and its implications for how we should live our lives. We argue that, in practice, a utilitarian should try to do as much good as possible while still abiding by commonsense moral virtues like integrity, trustworthiness, and law-abidingness, in order to advance social cooperation and mitigate the downside risk of miscalculation.

Chapter 7 examines how robust these practical recommendations are to various departures from strict utilitarian theory. While some alternative theories may yield radically divergent practical implications, we argue that a wide range of reasonable views ultimately converge on the core practical recommendation of utilitarian ethics—namely, to use a significant fraction of your time and/or money to help others, and to try to do so as effectively as possible, without violating commonsense moral constraints.

Prominent objections to utilitarianism are addressed in Chapter 8. We introduce a “toolkit” of general maneuvers available to utilitarians to address a wide range of objections, and then show how this toolkit can be used to address concerns about rights, demandingness, cluelessness, and more.


What matters most for utilitarianism is improving the well-being of all individuals, regardless of their gender, race, species, or geographical or temporal location.

All utilitarian theories share four key elements: consequentialism, welfarism, impartiality, and aggregationism. Classical utilitarianism includes two further elements: hedonism and totalism. Hedonism is the view that one’s well-being is determined by the balance of one’s positive and negative conscious experiences. The total view holds that the value of adding an additional person to an outcome is equal to the value of that person’s lifetime well-being, together with whatever effects they have on others’ well-being.

Utilitarian ethics has an intellectual tradition spanning centuries, during which it has prompted many heated debates. Critics of utilitarianism accuse the theory of disregarding rights and being overly demanding, among other objections. Advocates counter that the theory has attractive theoretical virtues and offers a compelling account of what fundamentally matters. If difficult tradeoffs were settled behind a veil of ignorance to minimize risk of bias, it would be rational for everyone involved to endorse utilitarian recommendations. Close examination of these competing arguments is required to come to an informed view of this controversial theory.

The next chapter discusses the four elements of utilitarian theories in greater depth and introduces several variants of utilitarianism.

How to Cite This Page

MacAskill, W., Meissner, D., and Chappell, R.Y. (2023). Introduction to Utilitarianism. In R.Y. Chappell, D. Meissner, and W. MacAskill (eds.), Introduction to Utilitarianism, <>, accessed .

Want to make the world a better place?

Learn how to put utilitarianism into practice:

Acting on Utilitarianism

Resources and Further Reading


The Classics

Further Reading

  1. Mòzǐ 32: 1, C. Fraser transl. ↩︎

  2. For more details, see Williams, E. G. (2015). The Possibility of an Ongoing Moral Catastrophe. Ethical Theory and Moral Practice, 18(5), 971–982. ↩︎

  3. For instance, Bentham commented on the issue of animal protection: “the question is not, Can they reason? nor, Can they talk? but, Can they suffer? Why should the law refuse its protection to any sensitive being? The time will come when humanity will extend its mantle over everything which breathes. We have begun by attending to the condition of slaves; we shall finish by softening that of all the animals which assist our labors or supply our wants.”

    Bentham, J. (1789). An Introduction to the Principles of Morals and Legislation. Bennett, J. (ed.), pp. 143–144. ↩︎

  4. Cf. Bentham, J. (1789). An Introduction to the Principles of Morals and Legislation. Bennett, J. (ed.); and Campos Boralevi, L. (2012). Bentham and the Oppressed. Berlin: De Gruyter. ↩︎

  5. The UK Parliament, The 1866 Women’s Suffrage petition: the first mass Votes for Women petition↩︎

  6. Mill attributes many of the ideas in The Subjection of Women to his wife, Harriet Taylor Mill. See Mill, J. S. (1873). Autobiography. Bennett, J. (ed.), p. 166. ↩︎

  7. Mill, J. S. (1869). The Subjection of Women. Bennett, J. (ed.), p. 1. ↩︎

  8. On extreme poverty, see: Singer, P. (2019). The Life You Can Save: Acting Now to End World Poverty, 2nd ed. The Life You Can Save, Bainbridge Island, WA and Sydney, available free at <>.

    On factory farming, see: Singer, P. (2023) Animal Liberation Now: The Definitive Classic Renewed, New York: HarperCollins. ↩︎

  9. This is most clear-cut in a fixed-population setting, where one’s actions do not affect the number or identity of people. For more complex cases, see the discussion of population ethics in Chapter 5. ↩︎

  10. However, when economists use the term “utility” they typically refer, instead, to the numerical representation of an individual’s preferences↩︎

  11. We use ‘happiness’ to refer to pleasant conscious experiences. Chapter 4: Theories of Well-Being explores whether well-being may involve more than this. ↩︎

  12. This definition applies to a fixed-population setting, where one’s actions do not affect the number or identity of people. There are aggregationist theories that differ in how they deal with variable-population settings. This is a technical issue, relevant to the discussion of population ethics in Chapter 5. Further note that non-welfarists might take things other than lives to contribute value to the world, which would then need to be included in the sum. We bracket this possibility for ease of exposition. ↩︎