“The core precept of utilitarianism is that we should make the world the best place we can. That means that, as far as it is within our power, we should bring about a world in which every individual has the highest possible level of well-being.”

Peter Singer

What Is Utilitarianism?

Utilitarianism is not a single viewpoint, but a family of related ethical theories. What these theories have in common is their focus on bringing about the best consequences for the world by improving the lives of all sentient beings. Utilitarianism holds that we should give equal moral consideration to the well-being of all individuals, regardless of characteristics such as their gender, race, nationality, or even species.1

The original and most influential version of utilitarianism is classical utilitarianism, first expressed in the writings of Jeremy Bentham and John Stuart Mill. Classical utilitarianism holds that what makes someone’s life go well is based on the subjective conscious experiences they have. A good life is filled with positive conscious experiences like enjoyment, happiness, and contentment, whereas a bad life contains many negative conscious experiences like suffering and pain. Classical utilitarianism holds that we should act so that the world contains the greatest sum total of positive experience over negative experience.

Continue reading: An Introduction to Utilitarianism

An Introduction to Utilitarianism: An Online Textbook

This website aims to provide a concise, accessible and engaging introduction to modern utilitarianism, functioning as an online textbook targeted at the undergraduate level. The content of this website aims to be understandable to a broad audience, avoiding philosophical jargon where possible and providing definitions where necessary.

A print edition of this textbook is available from Hackett Publishing

An Introduction to Utilitarianism (2024)

“This is the perfect introduction to utilitarianism: comprehensive, critical and accessible as a basis for classroom discussion or public debate.”

— Prof. Philip Pettit, Princeton / ANU

View Academic Endorsements

Acting on Utilitarianism

Utilitarianism has important implications for how we should think about leading an ethical life. Because utilitarianism weighs the well-being of everyone equally, it implies that we should make helping others a very significant part of our lives.

There are many pressing problems in the world today. Unfortunately, because our resources are scarce, we cannot solve all the world’s problems at once. What is more, not all ways of helping others are equally effective. According to utilitarianism we should carefully choose which problems to work on and by what means, based on how we can most improve the lives of everyone, counted equally. This involves taking seriously the question of how we can best use our time and money to help others.

A few moral projects appear especially pressing by utilitarian lights, such as fighting extreme poverty, reducing the suffering of animals on factory farms, and, in particular, ensuring that the long-term future goes as well as possible. People who will exist in the future greatly outnumber those who are alive today, and we may be able to take actions that affect their well-being. Therefore, one key concern for utilitarians is to promote the well-being of not only the current generation but of all generations to come.

Addressing these problems may involve donating generously to effective charities, choosing your career based on how to most help others, and encouraging other people to do the same.

Read: Acting on Utilitarianism


Utilitarian Thinkers

“Utilitarianism is a great idea with an awful name. It is, in my opinion, the most underrated and misunderstood idea in all of moral and political philosophy.”

— Joshua Greene



Who We Are

This website was written by Richard Yetter Chappell, Darius Meissner, and William MacAskill. Richard is an Associate Professor in Philosophy at the University of Miami and holds a PhD from Princeton University. Darius holds a degree in Philosophy, Politics and Economics from the University of Oxford and an M.A. in Security Studies from Georgetown University. William is an Associate Professor in Philosophy and Senior Research Fellow at the Global Priorities Institute at the University of Oxford.

We’re proud to have secured endorsements from prominent scholars, including at Harvard University, Princeton University, and New York University.

Read more about us.


  1. Of course, individuals of different species may differ drastically in their capacity to suffer or flourish: a typical human or dolphin may have vastly more well-being at stake than a typical mouse or chicken. The point is just that an equal amount of suffering matters equally no matter who it is that experiences it. ↩︎