used Kertbeny's terms in his book, Discovery of the Soul (1880). In 1886, Richard von Krafft-Ebing used the terms homosexual and heterosexual in his book Psychopathia Sexualis , probably borrowing them from Jager. Krafft-Ebing's book was so popular among both layman and doctors that the terms "heterosexual" and "homosexual" became the most