From the "Introduction": European Emperors, Kings, Kaisers and Tsars, and their Churches, forbade contraception, women's equality and divorce. Baptismal Certificates and class barriers dictated who could legally marry, attend school or the university, advance socially, and who could not. World War I finally swept them from power, but their dictates frequently remained as law, in a turbulent era of struggle for freedom and democracy, versus resurgent fascism and slavery. Hodann's History contains a clear discussion of these historical developments within the sexual reform and women's rights movements of Weimar Germany and Europe generally, in the early decades of the 1900s. The parallel advance of scientific knowledge on human sexuality is also detailed. Unlike many contemporary works on these subjects, History of Modern Morals is authored by a physician who lived the struggle, was a leader in it, got arrested by the Nazis for it, and intimately worked with other professionals who also had personally suffered for their work in the same social-sexual reform movement. His writings are therefore filled with a strong passion and vitality, and with many personal observations, anecdotes, and clarifying information not found elsewhere. Hodann's History is also unique in that he frequently and positively discusses the work of his contemporary and associate, Wilhelm Reich. This is especially important given their life-positive emphasis upon love and emotion in sexuality, and their distinction between natural-healthy heterosexual genitality versus neurotic and unhealthy sexual expressions. In the modern era of "politically correct" moral equivalence, this essential consideration has been diminished or erased from public discussion.