Richard Maurice Bucke (18 March 1837 – 19 February 1902), often called Maurice Bucke, was an important Canadian progressive psychiatrist in the late nineteenth century. An adventurer in his youth, he went on to study medicine, practice psychiatry in Ontario, and befriend a number of noted men of letters in Canada, the U.S., and England. In addition to writing and delivering professional papers, Bucke wrote three book-length studies: Man's Moral Nature, Walt Whitman, and – his best known work – Cosmic Consciousness, a classic in the modern study of mystical experience.