How others will see it. Marat/Sade was listed in the Guiness Book of World Records as the longest movie title. The full (and correct) title is The Persecution and Assassination of Jean-Paul Marat as Performed by the Inmates of the Asylum at Charenton Under the Direction of the Marquis de Sade. Not surprisingly, the movie is better known by its heavily abbreviated title.
With such a ponderous title, one expects it to be pretentious. It is not. Instead, it is chaotic, particularly the melee finale in which the inmates assault prison officials and their nun guards, while de Sade stands back and laughs at it all.
The weird chaos is interrupted by occasional philosophical exchanges between Marat and de Sade. Revolutionary Marat seeks to destroy the old Royalist order to install his unworkably complex philosophy of government by the people, which in practice is an unstable oligarchy that rules by whim and capital punishment. Libertine de Sade is scornful of activist government, particularly if its chief instrument is the guillotine.
Here we have Shakespearian British actors playing French mental patients during the reign of Napoleon. These patients, in turn, are playing real or allegorical French revolutionary figures from 1793.
In short, any Americans who stumble across this curious production will find it incomprehensible. Even if they can discern the British dialogue, they are unlikely to have passing knowledge of Marat, Danton, Robespierre, or even the Marquis de Sade.
Does one have to know about the French Revolution to appreciate the play? It helps, but since the production is deliberately chaotic anyway, removing the inner philosophical core still leaves its bizarre outer shell intact.
The typical dish or cable viewer, then, might utter "What the hell is this?" and gaze upon the weirdness only momentarily, without even having put down the remote.
How I felt about it. Marat is presented as a humorless intellectual figure, emotionally detached from the savage implications of an unimpeded government bent on murderous (and perhaps pointless) class revenge. de Sade actually comes off better, since he opposes Marat (in this play, although in real life, he wrote Marat's eulogy, according to wikipedia.com). A weird scene has de Sade tortured for his own pleasure by Glenda Jackson's long hair. Strange scenes can be felt but not always understood, and perhaps its impossible to do so.
The riot at film's end can be interpreted as a repudiation of Napoleon, or simply as a return of the inmates to their natural insane selves, instead of playing their stage characters.
Why would a traditional British troupe film an unconventional play based on French history? Perhaps the troupe was exploring the limits of what could be done, or gotten away with. But forty years later, it is a nearly forgotten experiment, rather than a glimpse of greatness.