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Utilitarianism: the greatest happiness principle
1789 onward· Idea or argument· Ethics & how to live
Well documentedSolid records, texts or physical evidence.
The view that the right act is whichever produces the greatest total happiness, counting everyone's happiness equally.
See it on the Philosophy map →The idea
The idea: only consequences matter, and 'everybody to count for one, nobody for more than one.' A government choosing between a hospital and a stadium should pick whichever does more total good. Bentham (1789) founded it as a tool for law reform; Mill (1861) refined it by ranking higher pleasures above lower ones; Henry Sidgwick systematized it in 1874. Main objection: it seems to permit terrible acts when totals come out ahead, such as a surgeon killing one patient to save five with the organs.
Why it matters
It became the default logic of public policy, from cost-benefit analysis to effective altruism, and remains one of the three main theories in ethics.
Think of it like
Like underwriting a deal: total every expected gain and loss for everyone affected, then choose the option with the best net result.
Where it comes from
Bentham's Introduction (printed 1780, published 1789), Mill's Utilitarianism (1863) and Sidgwick's The Methods of Ethics (1874); modern defenders include Peter Singer.
Still debated
Whether happiness can be measured and compared between people, and whether to judge single acts or general rules, still divides utilitarians themselves.
Inside this (1)
Connections (6)
▸Mozi and Mohism: impartial care anticipated the consequentialism of Utilitarianism: the greatest happiness principleDebated
The connection
Mozi judged every practice by whether it brought benefit (li 利, not the ritual li 禮): feeding the poor, growing the population, keeping order. He urged impartial care (jian ai 兼愛) and condemned lavish funerals and aggressive war as waste. Bentham's test, total happiness counted impartially, echoes this over two thousand years later, without any contact.
When and how
Warring States China, 5th–4th century BC, in the book Mozi; Bentham's parallel came in London in 1789. Modern scholars drew the comparison.
How sure are we?
Only by comparing texts; there was no historical link. Mohist writings were barely read even in China for two millennia and were unknown to Bentham.
Debates and open questions
Whether Mozi was a consequentialist at all; he measured wealth, population and order rather than happiness, and also appealed to Heaven's will (tian zhi 天志).
▸The categorical imperative rivals Utilitarianism: the greatest happiness principleWell documented
The connection
These are modern ethics' two great rival answers. Kant: some acts are wrong whatever the outcome, and people must never be used merely as means. Utilitarians: the right act maximizes total well-being. Test case: lying to a murderer to save a friend. Kant forbids it; a utilitarian requires it. Mill attacked Kant directly in Utilitarianism (1863).
When and how
Kant's Groundwork (1785) and Bentham's Introduction (1789) appeared four years apart, independently; Mill's critique came in London in 1861–63.
How we know
Mill argues Kant's examples show only that universal immorality has bad consequences; a 2020 survey found philosophers split roughly in thirds between these two and virtue ethics.
Debates and open questions
Whether they truly conflict; Derek Parfit's On What Matters (2011) argued the best versions converge, their defenders 'climbing the same mountain on different sides.'
▸Jeremy Bentham founded Utilitarianism: the greatest happiness principleWell documented
The connection
Bentham took the phrase 'the greatest happiness of the greatest number,' used earlier by Hutcheson, Beccaria and Priestley, and built it into a system for law. Laws and punishments should be judged solely by whether they increase total happiness, pleasure minus pain; his 'felicific calculus' scored pleasures and pains on seven dimensions, from intensity to extent, the number affected.
When and how
London: A Fragment on Government (1776) and An Introduction to the Principles of Morals and Legislation (printed 1780, published 1789).
How we know
His published works and manuscripts at University College London; Mill's 1838 essay 'Bentham' treats him as the school's founder.
Debates and open questions
Whether 'founded' is fair given his many predecessors; Bentham credited Priestley, and similar ideas appear in Hume, Helvétius and even ancient China's Mozi.
▸John Stuart Mill refined Utilitarianism: the greatest happiness principleWell documented
The connection
Mill defended Bentham's principle against the charge that it was a 'doctrine worthy only of swine' by ranking pleasures: those who know both prefer intellectual to bodily ones. 'It is better to be a human being dissatisfied than a pig satisfied; better to be Socrates dissatisfied than a fool satisfied.' He also tied justice and rights to utility.
When and how
London; first published as essays in Fraser's Magazine in 1861, then as the book Utilitarianism in 1863.
How we know
The text itself, still the most widely read defense of the theory and a standard university reading.
Debates and open questions
Whether his 'proof' works; G. E. Moore attacked it in 1903 for confusing 'desired' with 'desirable.' Whether Mill judged single acts or general rules is also debated.
▸Utilitarianism: the greatest happiness principle is applied by Peter Singer: the drowning child and Animal LiberationWell documented
The connection
Utilitarianism says the right act produces the most well-being, counting everyone equally. Singer applied this strictly: a child's life abroad counts as much as one nearby, and animals' suffering counts too. As Bentham wrote, 'The question is not, Can they reason? nor, Can they talk? but, Can they suffer?'
When and how
Singer studied at Oxford under R. M. Hare, a preference utilitarian; 'Famine, Affluence, and Morality' (1972) and Animal Liberation (1975) followed.
How we know
Singer calls himself a utilitarian, quotes Bentham in Animal Liberation, and lays out the framework in Practical Ethics (1979). He later moved from preference to pleasure-based utilitarianism (2014).
Debates and open questions
The drowning-child argument needs only a weaker principle, not full utilitarianism, so how much his conclusions depend on the theory is debated.
▸The trolley problem tests Utilitarianism: the greatest happiness principleWell documented
The connection
Utilitarianism counts outcomes: five lives beat one in both cases, so you should switch the trolley and also push the man. Most people accept the first but reject the second. That gap is a standard objection: either the footbridge intuition is wrong, as some utilitarians say, or the theory leaves something out.
When and how
Foot's 1967 paper and Thomson's footbridge (1976, 1985); Joshua Greene and Peter Singer later defended the utilitarian answer.
How we know
Surveys and lab studies consistently find most people switch but will not push; Greene's 2001 brain-imaging study in Science linked refusals to emotional responses.
Debates and open questions
Whether the footbridge intuition is moral insight or an emotional bias, as Greene and Singer argue, is a live debate.