Although mainly remembered as the author of what many critics consider the most important book on ethics written in nineteenth-century Britain, The Methods of Ethics (1874), Henry Sidgwick was a man of broad interests and wide-ranging knowledge. He studied classical languages and literature, and his lectures, addresses, and reviews dealt with history, economics, politics, and poetry, in addition to philosophy. His enthusiasm for spiritualism reflected his hope that scientific evidence of paranormal events would support religious belief. He also took practical steps to improve educational opportunities for women.

Sidgwick was born in Skipton, Yorkshire, on 31 May 1838, the third son and fourth of the six children of the Reverend William Sidgwick, the head of the local grammar school, and Mary Crofts Sidgwick. One of his brothers died when Sidgwick was two, and his father died the following year. After some wanderings, during which one of Sidgwick's sisters died, Mary Sidgwick...