Sexual Inversion: Studies in the Psychology of Sex

Henry Havelock Ellis, known as Havelock Ellis (born February 2, 1859, died July 8, 1939) was an English physician, writer, progressive intellectual and social reformer who studied human sexuality. He was co-author of the first medical textbook in English on homosexuality in 1897, and also published works on a variety of sexual practices and inclinations, as well as transgender psychology. He is credited with introducing the notions of narcissism and autoeroticism, later adopted by psychoanalysis.