Utilitarianism holds that the right action is the one producing the most good for the most people. It is the best known form of consequentialism, the wider view that outcomes determine rightness.

From Bentham to Mill

Jeremy Bentham set out the principle of utility in 1789: actions are approved in proportion as they tend to increase happiness and disapproved as they tend to diminish it. He treated pleasure as measurable in quantity and counted every person's equally, which was a radical levelling claim in its period.

John Stuart Mill refined it in Utilitarianism (1863) by distinguishing higher from lower pleasures. Some satisfactions, he argued, are preferred by anyone acquainted with both, and a theory that counts only intensity misses that. Mill also stressed that the standard is the general happiness rather than the agent's own.

Act and rule

Act utilitarianism applies the calculation to each decision. Rule utilitarianism applies it to the rule the decision falls under, and asks which rule, generally followed, produces the most good. The distinction matters because act utilitarianism can license one-off betrayals that would be ruinous as a practice, while rule utilitarianism recovers something close to ordinary moral duties without borrowing from deontology.

The standing objections

Two objections recur. The first is that the theory permits injustice when the arithmetic favors it — framing an innocent person to prevent a riot is the textbook case. The second is that it demands too much, since at any moment there is usually some further good you could be producing elsewhere.

Defenders answer that the calculations are not as permissive as they look: practices of trust and rights are themselves enormously useful, so a serious utilitarian has strong reasons to protect them. Critics reply that protecting rights only because they happen to pay is a thin kind of protection. That exchange is the live center of the debate in ethics.