Bentham's Hedonic Calculus and the Principle of Utility

Jeremy Bentham (1748–1832), born in London and admitted to Oxford at the unusually young age of twelve, set out the founding statement of philosophical utilitarianism in An Introduction to the Principles of Morals and Legislation, printed in 1780 and formally published in 1789. The work opens with one of the most quoted lines in modern ethics, declaring that nature has placed mankind under the governance of two sovereign masters, pain and pleasure, and that it is for them alone to point out what people ought to do. From this claim Bentham derives the principle of utility, also called the greatest-happiness principle: an action, law, or institution is right insofar as it tends to augment the happiness of those affected by it, and wrong insofar as it tends to diminish it. Bentham intended utility as a genuinely scientific standard for legislation and morals alike, replacing appeals to natural law, divine command, or the "moral sense" theories of Francis Hutcheson and the Earl of Shaftesbury with a single, calculable metric grounded in pleasure and pain. Hutcheson himself had already used a version of the phrase "the greatest happiness for the greatest numbers" in his 1725 An Inquiry into the Original of our Ideas of Beauty and Virtue, and the Italian jurist Cesare Beccaria's Dei delitti e delle pene (1764) supplied Bentham with a further model of utility applied directly to penal reform, an application central to Bentham's own lifelong campaigns against the death penalty and in favor of prison reform, most famously through his design for the Panopticon prison.