The Marquis de Sade spent almost 30 years of his life in various prisons, and what got him there had almost nothing to do with his writing. His mother-in-law, Mme de Montreuil, having offered up her wealthy daughter to obtain De Sade's noble name, became outraged by his sexual scandals with prostitutes and with her other and most favoured daughter. Finally, Mme de Montreuil, "the Hyena", as De Sade called her, cut her losses and had him imprisoned under a lettre de cachet -- by which a prisoner's family paid his "rent" to keep him in prison.

De Sade's vows of vengeance were stoked up during all those years locked up in Vincennes and the Bastille and when he was freed after the revolution, becoming an official of the radical Section des Picques in Paris, he had the opportunity to wreak that vengeance. The Montreuils fell under suspicion but this is how he described what he did: "I caused the Montreuils to be moved on to a list of exculpated persons. If I had said a word, they would have been roughly handled. I held my tongue; there, you see how I avenge myself!"

De Sade is much more of a protean, amphibian creature, morphing from noble to revolutionary, and there is a great deal more to him, much of it decidedly more complex, interesting, and baffling, than the point that Quills, the film of his life, tirelessly belabours: that he is a martyr to the oppression and censorship of church and state.

The movie opens with De Sade at an upper window watching the guillotine at work during the French revolution's bloodletting terror of September 1793-July 1794. Much later, we are told that this kind of activity explains the sanguinary streak in his writing. In fact, his bloodiest and best work, 120 Days of Sodom, was written in the Bastille -- obviously before the revolution. This is an important book, and to suggest that it was written late in De Sade's life in the asylum at Charenton, where he spent the last 11 years of his life until his death in 1814, does the book and the viewer a disservice.

De Sade was not at the height of his literary career nor of his literary powers at Charenton. Nor was he the imposing physical specimen implied by the tall, trim figure of the Australian actor Geoffrey Rush, who plays him in the film. At most, De Sade was of middling height. More to the point, his suffering and unhappiness had taken their toll. He had eaten himself into a considerable, even a grotesque, obesity. He was fortunate at Charenton to have come under the protection of the asylum's progressive and gentle director, the Abbé de Coulmier, who encouraged De Sade to direct the other inmates and some professional actors in plays that soon attracted substantial and even fashionable audiences. This new therapy certainly had a beneficial effect on De Sade's spirit and energy. But the plays he put on were conventional warhorses of the Paris stage. There was no violent and sexual orgy scene as the movie depicts.

Just as Rush in no way resembles De Sade, the handsome Joaquin Phoenix could never be mistaken for Coulmier, who, in fact, stood only four feet tall and was severely misshapen. This odd couple came to have a very good effect on each other. Coulmier was perhaps the first true male friend Sade made in his life, and this may indicate that some improvement had taken place in his mental health.

The movie sacrifices the truth of this relationship and of Coulmier's own fate to a surreal and didactic conclusion that has no connection with the truth, and is probably overwrought even as a twist of a fictional plot. Indeed, De Sade's hideous death in the movie is nothing like the truth, for he died in his sleep, in his 74th year, as peacefully as any good Christian. The villain of the piece is made out to be Dr Royer-Collard. True, there was such a person, and he did disapprove of Coulmier's drama therapy as well as De Sade's presence in a hospital environment when he should have been in a prison. But De Sade had never been convicted of anything, including publishing pornography. When Royer-Collard was finally able to install his protege as Coulmier's replacement, the drama therapy had long ago been suspended, and while De Sade did lose some of his privileges, he was already in the last year of his life.

Of all the characters in the movie, Royer-Collard, played by Michael Caine, is the one that is the most inflated for melodramatic and didactic effect: he is given an underage orphan bride straight out of a nunnery; he is made into a sadistic husband and a fiendish tyrant in the asylum; and he is provided with the most implausible, seemingly ironic twist of fate to perform at the end.

The single didactic message of the movie is that the seemingly good people are all bad underneath, are all hypocrites, while the seemingly bad person, De Sade, probably has some redeeming qualities: he tells it like it is, and apparently did not take sexual advantage of the young chambermaid (Madeleine LeClerc, played by Kate Winslet) with whom he was so friendly. However, De Sade's last journal makes it clear that he had been having a regular sexual liaison with the 18-year-old chambermaid from her early teens until the week before he died.

In the film, the chambermaid/laundress smuggles De Sade's manuscripts out to his Paris publisher. In reality, this task was performed, quite unmelodramatically, by De Sade's companion of many years, Mme Quesnet, who was permitted to have a room at Charenton so she could be with him. The movie totally ignores this stable relationship and instead intrudes impossible and misleading scenes with De Sade's wife, who had formally separated from him after the revolution.

Moreover the manuscripts Mme Quesnet smuggled out were not the dangerous novel Justine (whose much earlier publication had made his embarrassed family seek to hide him away in Charenton), but primarily a number of fairly conventional novels, as well as some stage plays he had written in his youth and which he hoped to have performed by the Comédie Française. He kept revising them in vain hopes of their acceptance.

In the last year of his life, he received yet another publisher's rejection letter. This time, he could not misinterpret its brutal clarity:"truly reprehensible... such a capital fault in a subject like this...inventions impossible not to find unfortunate... sheer 'melodrama'...written in verse that almost never rises to the level of good prose".

What is the harm in misrepresenting the true nature of De Sade's life and career? After all, some of the events in the movie did really happen to him at some time or other. Of course, playwrights and movie-makers are not under oath when they show us their work. And without condensation, there can be no art. The artist must make choices to put some things in and leave others out, a rule that applies to biographers as well. But if a biographer makes a mish-mash of his subject, there is hell to pay. If a movie does the same, there could be talk of Academy awards for all concerned, as there has been in this case.

The viewer of Quills should be aware that what he is seeing is not De Sade. To see if Quills is valid in its own terms, let the viewer imagine it is about someone else, let us say the Marquis de Newcastle, and that the scene is Bedlam and then see if the movie makes any sense.

The movie-makers and reviewers alike seem to think that the main point of De Sade's life and writing is to oppose censorship. In fact, his main obsession was to push the limits -- sexual, spiritual, and political -- as a means of feeling out the limits of his times and of his own mind. If there were no limits, there would be no meaning. When De Sade performed a sexual act with a prostitute and a communion wafer, he cried, "If you are God, avenge yourself!" The perversions were rhetorical acts at least as much as sexual ones. They were a way of opening a dialogue with the powers that be and with nature itself.

In the same way, censorship was important to De Sade's way of thinking; he felt compelled to challenge it. Quills simplifies De Sade into a modern "victim" and over-emphasises his potential as a focus for liberal-political meanings when, in fact, his life and perhaps his literary intentions -- if you think of him as a satirist -- can be seen as an object lesson, warning against the excesses of cultural relativism and nihilism; a very modern lesson, it would seem.

De Sade was an extremist on both sides. He plunged as deeply into the psyche as anyone had done before or since, yet he also sought some meaning, even if it were only punishment from above. "If you are God, avenge yourself!" God did not have to. The pity is that Quills did.