More sinned against than sinning?

<i>Letters from Prison</i> by the Marquis de Sade. Translated by Richard Seaver (Harvill, &pound;20, 401pp)

Outcast, pornographer, iconoclast, prisoner of conscience: few people have been granted so many revisions of reputation as the Marquis de Sade, now the subject of two new films. This selection of his prison letters offers startling insights into the mind of the divine, or infernal, marquis. They were written during the 13 years Sade spent imprisoned under the authority of lettres de cachet issued by French monarchs - an incarceration without trial that meant he was, in effect, a political prisoner.

Outcast, pornographer, iconoclast, prisoner of conscience: few people have been granted so many revisions of reputation as the Marquis de Sade, now the subject of two new films. This selection of his prison letters offers startling insights into the mind of the divine, or infernal, marquis. They were written during the 13 years Sade spent imprisoned under the authority of lettres de cachet issued by French monarchs - an incarceration without trial that meant he was, in effect, a political prisoner.

The earliest letters were written in the grim fortress of Vincennes, where Sade was taken in 1777. Anything but a stoic, he railed against his fate and threatened suicide. He can scarcely have imagined that he would languish in Vincennes for seven years, then find himself transferred without notice to the equally forbidding Bastille. On 2 July 1789, infuriated by a decision to suspend his daily walk, Sade used a makeshift megaphone to harangue the pre-revolutionary populace from his window, an act that resulted in his hurried transfer to the Charenton asylum.

When the Bastille was stormed 12 days later, he was thus no longer in residence and had to wait until the following spring, when the National Assembly abolished lettres de cachet, to regain his freedom. He emerged obese from over-eating and lack of exercise, with his health broken and his eyesight damaged. Several of his prison works were lost, and he was never to know that The 120 Days of Sodom had survived and would finally be published more than a century later, inflating his already sulphurous reputation.

Sade's frequent protestations that he was guilty only of rough treatment of "whores", in common with thousands of other men of his rank, reveal his contempt for working-class women. Yet he was right to insist on a distinction between the acts he imagined and those he committed. "Yes, I am a libertine," he wrote to his wife on the fourth anniversary of his incarceration at Vincennes. "I have conceived everything that can be conceived in that area, but I have certainly not practised everything I have conceived and never shall".

The ferocity of his imagination is displayed in occasional outbursts that recall the calculated outrages of his fiction. In a 1783 letter addressed "To the Stupid Scoundrels Who Are Tormenting Me", Sade describes the tortures he would like to see inflicted on his mother-in-law, whom he blamed for his imprisonment: "I saw her skinned alive, dragged over thistles, and then tossed into a vat of vinegar". Yet ten years later, when Sade was enjoying a brief transformation in his fortunes (appointed a revolutionary judge), he intervened on behalf of his parents-in-law and almost certainly saved them from the guillotine.

It is contradictions like this that enrage Sade's critics, revealing a man who, in spite of the excesses of his youth and the barbarism of his mature works, was cultured, witty and humane. He was also fussy, vain and self-obsessed. The errands he imposed on his long-suffering wife, Renée-Pelagie, included not just demands for clean linen and pots of jam but sending her off to buy masturbatory aids made to his specification, which understandably mortified the poor woman.

Yet the letters also establish the link between Sade's lengthy incarceration and the studied cruelty of his novels. They must rank as one of the most intelligent accounts of solitary confinement and imprisonment without trial ever written, justifying his claim about their disastrous effects on his character. In a letter composed before Sade declared his atheism, he wrote that "the only fruits I can cull from such a situation is to become worse than I already was, because of the excess of hate that I shall be forced to feel towards my fellow-men".

At times his obsessions get the better of him, prompting him to harangue Renée-Pelagie about the non-existent secret signals he discerns in her replies to him. On other occasions, he writes with unusual candour, revealing an inability to ejaculate that almost certainly lies at the heart of his baroque sexual fantasies.

Yet the letters are also a testament to his zest for living. After six years of imprisonment, Sade is still sending his wife shopping lists that include two dozen meringues, two dozen lemon cakes, and a copy of the architectural plans for the new Italian opera house in Paris. His gaolers may have perverted his bizarre spirit, but they never succeeded in breaking it.