The English philosopher and moralist Henry Sidgwick (1838-1900) was the author of The Methods of Ethics, which has been described as the "best treatise on moral theory that has ever been written."

Henry Sidgwick was born in Yorkshire and attended Rugby before entering Trinity College, Cambridge. After a distinguished undergraduate career, he was elected a fellow in 1859. Because he could not in conscience subscribe to the Thirty-nine Articles as a condition for holding a fellowship, Sidgwick resigned but remained at Cambridge as a lecturer. He became Knightbridge professor of moral thought in 1883. Together with his wife, Eleanor, a sister of Arthur Balfour, the British prime minister, he helped to establish Newnham, the Cambridge University college for women. Sidgwick was also one of the founders and the first president of the influential Society for Psychical Research. In addition to the classic The Methods of Ethics (1874), Sidgwick's writings include Principles...