Henry Sidgwick was a Cambridge philosopher, psychic researcher and educational reformer, whose works in practical philosophy, especially The Methods of Ethics (1874), brought classical utilitarianism to its peak of theoretical sophistication and drew out the deep conflicts within that tradition, perhaps within the age of British imperialism itself. Sidgwick was profoundly influenced by J.S. Mill, but his version of utilitarianism – the view that those social or individual actions are right that maximize aggregate happiness – also revived certain Benthamite doctrines, though with more cogent accounts of ultimate good as pleasure, of total versus average utility, and of the analytical or deductive method. Yet Sidgwick was a cognitivist in ethics who sought both to ground utilitarianism on fundamental intuitions and to encompass within it the principles of common-sense ethics (truthfulness, fidelity, justice, etc.); his highly eclectic practical philosophy assimilated much of the ratio...