Aurel Kolnai wrote his Sexualethik in the Vienna of the 'twenties, not long after the end of the first world war and the collapse of the Habsburg Empire. Although not one to try and tell people what they should do or think, he was nevertheless a passionate believer in reason and rigorous thought about the data of experience and he strongly believed that he had something important to say on virtually every aspect of sexual morality. Despite being personally inclined to a puritan attitude, he possessed a voracious curiosity about sex, an astonishingly objective approach to experience and a determination minutely to question people of all different sexual persuasions, with the broad aim of trying to lay bare the meaning and significance of sex in all its main forms, approved and disapproved. This first English translation of an important part of Kolnai's work by leading Kolnai scholar Francis Dunlop will be an invaluable addition to the literature on sexual ethics and of great interest to moral philosophers, moral theologians and students of counselling, sex therapy and sexology. The book contains a preface by Roger Scruton and a detailed introduction by the translator.