In 1923, Helene Deutsch became the first psychoanalyst to write a book about female psychology, called Psychoanalysis of the Sexual Functions of Women in English. Her interest in the subject, along with that of Karen Horney, helped to push her mentor Sigmund Freud, who did not like being left behind, into writing articles about female psychology. When Deutsch was completing her manuscript, she wrote to her husband, Felix, “It brings something new to this terra incognita in analysis—I believe, the first ray of light on the unappreciated female libido.” For her to draw attention to the female libido in that era was implicitly to amend Freud’s own outlook. At the same time, Deutsch was pioneering the importance of motherhood. Other psychoanalysts of the period, such as Otto Rank, Sandor Ferenczi, and Georg Groddeck, were also intrigued by the neglected role of mothering, but Deutsch was the one to insist on its special significance for female psychology. Although she always remained loyal to Freud’s conceptual framework, her writings were an outgrowth of her own personal experiences and insight.