Leslie Stephen (1832–1904) was an English biographer, and a writer on philosophy, ethics and literature. He was educated at Eton, King's College, London, and then Trinity College in Cambridge, where he remained as a fellow and a tutor for his entire career. He was also a keen mountaineer, taking part in first ascents of nine peaks in the Alps. He served as the first editor (1885–91) of the Dictionary of National Biography and in 1871 he became editor of the Cornhill Magazine. During his eleven-year tenure he wrote two successful books on ethics, of which this work, published in 1882, was one. It was widely adopted as a standard textbook on moral philosophy, and became one of the most influential publications on the ideas of evolutionary ethics that had been inspired by Darwin's theory of evolution by natural selection.