Otto Weininger (1880-1903) was an Austrian philosopher, the son of a Jewish goldsmith, born in Vienna when it was part of the Austro-Hungarian Empire. He studied philosophy and psychology at the University of Vienna, also taking courses in natural sciences and medicine. He acquired a knowledge of a wide range of languages, including Greek, Latin, French, and English, then later Spanish and Italian, and a smattering of the Scandinavian languages. In 1901 he tried unsuccessfully to find a publisher for his work Eros and Psyche which he submitted as his thesis in 1902. His thesis was accepted and he received his Ph.D degree in July 1902, becoming an enthusiastic convert to Protestantism shortly thereafter. At this time he saw performances of Wagner's Parsifal in Bayreuth and Ibsen's Peer Gynt in Oslo, both of which left a deep impression on him. On his return to Vienna he fell into a deep depression and formed the idea of taking his own life. In June 1903, after many months of hard work, his book Sex and Character - an attempt "to place sex relations in a new and decisive light" - was published. The book was made up of his original thesis together with three additional chapters: 'The Nature of Woman and her Relation to the Universe', 'Judaism', and 'Woman and Humanity'. Weininger was disappointed that, though not received negatively, the book did not create the stir he had anticipated. On 3 October he took a room in the house where Beethoven had died and the following day was found mortally wounded, having shot himself in the chest. He died in the General Hospital and was buried in Vienna's Protestant Cemetery. Sex and Character gained popularity after his suicide and greatly influenced both Wittgenstein and Strindberg. In it he argues that all people are composed of a mixture of male and female substance, and a significant part of the book is about the nature of genius. This English language edition is reprinted from the authorised translation from the sixth German edition of Geschlecht und Charakter (Sex and Character).