“Either kill me or take me like this, for I will not change,” wrote the imprisoned Marquis de Sade to his wife in 1783. It could only be one or the other for the most extreme author of the 18th Century. Sade, an unstoppable libertine, was in the middle of what would be an 11-year prison sentence, but he would not recant his principles or his tastes to get out of jail. Any diversion from his true nature was, for the marquis, equivalent to death.

Sade, rediscovered but still widely misunderstood, is the subject of two exhibitions in Paris that offer a new chance to rediscover one of the most darkly influential figures of European culture. Later this month the Musée d’Orsay opens Sade: Attacking the Sun, an ambitious new exhibition that rereads the history of modern art through the lens of his radical writings. Just around the corner, the Musée des Lettres et Manuscrits is presenting an exhibition of Sade’s letters and books, including the manuscript for his audacious and stomach-turning novel The 120 Days of Sodom. Both should allow viewers to think more deeply about Sade’s time and ours, and how thoroughly the one informs the other.

Our story of the 18th Century – not just in France but also in its fellow child of the age, the United States – can sometimes be a little one-sided, a little deceptive. The Enlightenment has come to mean reason, rationality, science, humanism, but that was never the whole story of the era. Sade, who died two hundred years ago this December, is unquestionably an Enlightenment figure. He greatly admired Rousseau, an author his jailers refused to let him read. Yet he struck the first blow (and Sade would like that metaphor) against the primacy of reason and rationality, and in favour of rebellion, extremity, and anti-humanism. Those are themes that scandalized the great and the good of the period, but they have resounded through the art, literature, and philosophy of the last two centuries.

Vice principle

Donatien Alphonse François de Sade, born in 1740, was a hugely complicated person. He was an aristocrat, but also a hard-left figure and delegate to the National Convention during the French Revolution who renounced his title during the Reign of Terror. He wrote some of the most provocative novels ever composed, but also bland and conventional plays that were not at all obscene. And of course, he had a marked taste for rougher forms of sexual intercourse: practices which now bear his name, but which an even cursory study of 18th-Century literature shows, were not exactly unique for the time. As Michel Foucault, the great historian of sexuality, once observed, sadism is not “a practice as old as Eros,” but rather “a massive cultural fact which appeared precisely at the end of the eighteenth century.”

Like Voltaire and Rousseau before him, Sade wrote novels that had to be read in two ways at once: as entertainments, but also as philosophical treatises. Even at his most outrageous, Sade was not really a pornographic writer. His early 120 Days of Sodom, with its endless lists of slicings, fractures, immolations, exsanguinations and death, offers no sexual titillation at all. Even his best novel, Justine, featuring a libertine priest defiling a girl with a strategically inserted communion wafer, scandalised French society not for any pornographic excess, but for its pitch-black moral vision – in which abusing other humans is not just acceptable but positively virtuous. Sade took Immanuel Kant’s categorical insistence that humans must do their duty and turned it on its head. True morality, for Sade, entailed following your darkest and most destructive passions to their farthest possible ends, even at the expense of other human life. (The whips are for beginners: Sade had no particular problem with murder, though he was an unsparing opponent of the death penalty. To kill a man in passion was one thing, but to rationalise killing by law was barbarous.)