In her study of eighteenth-century literature and medical treatises, Mary McAlpin takes up the widespread belief among cultural philosophers of the French Enlightenment that society was gravely endangered by the effects of hyper-civilization. McAlpin''s study explores a strong thread in this rhetoric of decline: the belief that premature puberty in young urban girls, supposedly brought on by their exposure to lascivious images, titillating novels, and lewd conversations, was the source of an increasing moral and physical degeneration. In how-to hygiene books intended for parents, the medical community declared that the only cure for this obviously involuntary departure from the "natural" path of sexual development was the increased surveillance of young girls. As these treatises by vitalist and vitalist-inspired physiologists became increasingly common in the 1760s, McAlpin shows, so, too, did the presence of young, vulnerable, and virginal heroines in the era''s novels. Analyzing novels by, among others, Jean-Jacques Rousseau, Denis Diderot, and Choderlos de Laclos, she offers physiologically based readings of many of the period''s most famous heroines within the context of an eighteenth-century discourse on women and heterosexual desire that broke with earlier periods in recasting female and male desire as qualitatively distinct. Her study persuasively argues that the Western view of women''s sexuality as a mysterious, nebulous force-Freud''s "dark continent"-has its secular origins in the mid-eighteenth century.