Modern sexology was introduced by the Berlin-based Magnus Hirschfeld, who was born 150 years ago. He revolutionized the physician-patient relationship by introducing new terms of sexual behavior. His theory of "sexual in-betweens" paved the way for new concepts in sexual therapy, including hormonal pills in urological practice. Some of his colleagues developed the idea of a rejuvenation of male organism by sterilization. Many urologists had learned this operation in 1920s, which thus unintentionally enabled the National Socialists to quickly implement racial hygiene laws after 1933.
Keywords: Bernhard Schapiro; Hormonal therapy; Magnus Hirschfeld; Sexual history; Vasectomy.