Drawing upon the writings of literary figures such as Diderot, Rousseau, Zola, Flaubert, and Huysmans, and physicians and psychologists such as Tardieu, Binet, and Charcot, Vernon Rosario argues that the modern idea of the perverse first emerged in late 18th-century France and was shaped largely by the strange confluence of medical writings, patient confessions, and literary narratives. Filled with extraordinary case studies and written in prose that is as lively and entertaining as it is insightful, this book offers both a history of the erotic imagination and its narrative expressions, as well as a fascinating mirror in which our contemporary ambivalence about sexuality - from the acrimonious rhetoric of family values to censorship of pornography and hostility towards gays - takes on surprising new significance.