Jean-Jacques Rousseau mentions his older brother François only two times in his classic Confessions. In The Only Son, Stéphane Audeguy resurrects Rousseau's forgotten brother in a picaresque tale that brings to life the secret world of eighteenth-century Paris.

Instructed at an early age in the philosophy of libertinage by a decadent aristocrat and later apprenticed to a clock maker, François is ultimately disowned by his family and flees to Paris's underworld. There he finds work in a brothel that caters to politicians and clergy and begins his personal study of the varieties of sexual desire - to its most arcane proclivities. Audeguy uses the libertine's progress to explore the interplay between the individual and society, much in the tradition of Jean-Jacques, but with a very different emphasis. Bold, erotic, and historically fascinating, The Only Son is, in many ways, the anti-Confessions - François' own, decidedly different, portrait of human nature.