Utilitarianism is the doctrine that actions are right if they are useful or for the benefit of a majority or if an action is right if it promotes happiness. The greatest happiness of the greatest number of people should be the guiding principle of conduct.
Utilitarianism is an ethical theory that states that the best action is the one that maximizes utility. “Utility” is defined in various ways, usually in terms of the well-being of sentient entities, such as human beings and other animals. Jeremy Bentham, the founder of utilitarianism, described utility as the sum of all pleasure that results from an action, minus the suffering of anyone involved in the action. Utilitarianism is a version of consequentialism, which states that the consequences of any action are the only standard of right and wrong. Unlike other forms of consequentialism, such as egoism, utilitarianism considers all interests equally.
Proponents of utilitarianism have disagreed on a number of points. Should individual acts conform to utility (act utilitarianism)? Or, should agents conform to ethical rules (rule utilitarianism)? Should utility be calculated as an aggregate (total utilitarianism) or as an average (average utilitarianism)?
Though the seeds of the theory can be found in the hedonists Aristippus and Epicurus, who viewed happiness as the only good, the tradition of utilitarianism properly begins with Bentham, and has included John Stuart Mill, Henry Sidgwick, R. M. Hare and Peter Singer. It has been applied to social welfare economics, the crisis of global poverty, the ethics of raising animals for food and the importance of avoiding existential risks to humanity.
Jeremy Bentham was an English philosopher, jurist, and social reformer. He is regarded as the founder of modern utilitarianism. Bentham’s book An Introduction to the Principles of Morals and Legislation was printed in 1780 but not published until 1789. Bentham’s work opens with a statement of the principle of utility:
Nature has placed mankind under the governance of two sovereign masters, pain and pleasure. It is for them alone to point out what we ought to do… By the principle of utility is meant that principle which approves or disapproves of every action whatsoever according to the tendency it appears to have to augment or diminish the happiness of the party whose interest is in question: or, what is the same thing in other words to promote or to oppose that happiness. I say of every action whatsoever, and therefore not only of every action of a private individual, but of every measure of government.
Although utilitarianism is usually thought to start with Jeremy Bentham, there were earlier writers who presented theories that were strikingly similar. In An Enquiry Concerning the Principles of Morals, David Hume writes:
“In all determinations of morality, this circumstance of public utility is ever principally in view; and wherever disputes arise, either in philosophy or common life, concerning the bounds of duty, the question cannot, by any means, be decided with greater certainty, than by ascertaining, on any side, the true interests of mankind. If any false opinion, embraced from appearances, has been found to prevail; as soon as further experience and sounder reasoning have given us juster notions of human affairs, we retract our first sentiment, and adjust anew the boundaries of moral good and evil.”