The central aim of John Stuart Mill’s Utilitarianism is to defend the view that those acts that produce the greatest happiness of the greatest number of people are right and good. This ethical position did not originate with Mill. An influential predecessor, Jeremy Bentham, earlier championed pleasure and pain as the sole criteria for judging what is good and bad. The utility yardstick measures good by asking: Does an act increase pleasure, and does it decrease pain? Bentham’s crude “Push-pin is as good as poetry” interpretation of the yardstick led to numerous criticisms. Therefore, Mill states the principle of utility in its most defensible form both to counter some specific criticisms of it and to make clear what the sanctions of the principle are. He also offers a proof of the principle. The work concludes with a discussion of the relation of utility to justice.