Who was Sabina Spielrein? Her dramatic life story is most famous for her notorious affair with Carl Jung, dramatised in the film A Dangerous Method starring Keira Knightley. Yet she was a woman who overcame family and psychiatric abuse to become an original thinker in the field of psychotherapy. This is the first biography to put her life and ideas at the centre of the story, and to examine Spielrein's key role in the development of psychoanalysis and in the rift between Jung and Freud. Drawing on fresh research into Spielrein's diaries, papers and correspondence, John Launer tells the story of a passionate woman who transformed herself from one of Jung's disturbed patients into a leading figure in Western psychology, then the Soviet intelligentsia, before losing her life in the Holocaust. At the heart of Sex Versus Survival is the gripping tale of Spielrein and Jung's tumultuous affair, which played such an important role in both of their lives and intellectual journeys. Launer shows how Spielrein's overlooked ideas - rejected by Jung and Freud, but substantially vindicated by later developments in psychology and evolutionary biology - may represent the last and most important stage in the rediscovery of an extraordinary life.