Turn-of-the-century Vienna is remembered as an aesthetic, erotic and intellectual world: the birthplace of Freud and psychoanalysis, the waltz, and the novels of Schnitzler. The contexts of this cultural vibrancy, Chandak Sengoopta argues, were darker and more complex than we might imagine. This provocative, enlightening study explores the milieu in which the philosopher Otto Weininger (1880-1903) wrote his controversial book "Sex and Character". Shortly after its publication, Weininger committed suicide at the age of 23. His book, which argued that women and Jews were mere sexual beings who lacked individuality, became a bestseller. Hailed as a genius by intellectuals such as Ludwig Wittgenstein and Karl Kraus, Weininger was admired, not for his prejudices, but for his engagement with the central issues of the time - the nature and meanings of identity. Sengoopta pays particular attention to how Weininger appropriated scientific language and data to defend his views and examines the scientific theories themselves.