Donald Thomas finds it remarkable, as anyone should, that the Marquis de Sade died a defeated man--imprisoned most of his life as a criminal or a lunatic, forbidden to write the self-revelatory books that assuaged his thwarted desires, reduced to composing only innocuous, moralistic tales, with no hope of ever having his suppressed writings known--and yet he became The Divine Marquis. Thomas surveys Sade's tormented fife and the works that survived him and attributes the posthumous ascendancy of Sade's reputation to a change in cultural ideals: whereas Sade's contemporaries found his tastes in pleasure bestial, irredeemably immoral, or at best insane, later generations saw in them a protest against oppressive conventions and authority, an expression of man's deepest irrationality, and the natural disorientation of human beings in a Godless world. Thomas shares these high valuations but tempers them with the sensible suggestion that some of Sade's writings satirized the clergy and the anarchy of the French Revolution. Thomas does not examine the psychological springs of Sade's unrestrained instincts, but he shows that Sade had no monopoly in his time on extravagant libertinage and the erotic uses of cruelty. And it is with amused irony that he records a phrenologist's judgment upon Sade's exhumed skull: ""Similar in all parts to that of a Father of the Church."" There is no new information here, but the many illustrations and Thomas' graceful, assured style and controlled wit make this an engaging, thoughtful introduction to an extraordinary man.