What utilitarianism asks of you

The greatest happiness of the greatest number. It is one of the few philosophical positions almost everyone can state, and one of the few that most people think they have already rejected. Both facts get in the way of understanding what it actually claims.

Three claims, not one

Classical utilitarianism is a stack of three separate commitments, and most disagreements are really disagreements about one of them rather than the whole.

1. Only consequences matter when judging an action. Intentions and rules are useful, but only because of what they tend to produce.
2. The consequence that matters is wellbeing — pleasure and the absence of suffering, in the original version.
3. Everyone's wellbeing counts equally, including strangers, and for later utilitarians including animals.

The third claim is the radical one. It rules out treating your own interests, your family or your country as having special weight in the calculation. Bentham's formulation — each to count for one, nobody for more than one — was a genuinely subversive thing to write in the 1780s, and it remains the part of the theory that people find hardest to live with.

The standard objections

Three objections do most of the work against it. That it permits atrocities if the sums come out right — the transplant surgeon who kills one patient to save five. That it is too demanding, since there is always something better you could be doing with your money and time. And that it cannot account for the ordinary moral weight of promises, loyalties and projects, which Bernard Williams argued amounts to alienating a person from their own life.

The responses are well developed and worth reading rather than summarising. What is worth saying here is that the theory has been unusually productive even for people who reject it: cost-benefit analysis, most of welfare economics, the modern animal welfare movement and effective altruism all descend from it, and they inherit its problems along with its clarity.

This piece is an introduction, not an argument. It states the position and the standard objections without settling them — which is the right ambition for a first pass at a subject this large.