Stanley Kubrick once said, "The Holocaust is about six million people who get killed. Schindler's List was about six hundred people who don't," which is actually a pretty fair criticism if you stop and think about it. By the same token, we might call the exhausting 1985 documentary Shoah a movie about a few dozen people who didn't die, although not all of them seem to have survived to quite the same degree.

Beginning in the latter half of the 1970s, the French filmmaker Claude Lanzmann set about collecting the testimony of Holocaust survivors, witnesses, and perpetrators. After several years of filming and a couple more of editing, he released one of the truly staggering achievements in cinema history: a two-part feature consisting of almost nine and a half hours of talking head interviews, occasionally set against Lanzmann's footage of the concentration camps and surrounding towns of Poland and Czechoslovakia. Not one second of archival material was used, not even a still photograph; only the words of people who were there, and grainy 16mm shots of moss-covered buildings and ruined foundations. On paper, it sounds like the most dully intellectual project that could be conceived. In practice, it competes only with Alain Resnais's nightmarish 1955 short Night and Fog to be the most devastating and comprehensive document about the Holocaust yet produced.

Paradoxically, this nine hour endurance test moves farther away from its seeming purpose the deeper into it we get: while it may seem that the chief goal of creating a documentary of such magnitude is to write the definitive statement - This above all is what we have learned as a species because of the Holocaust - Lanzmann's ultimate conclusion (I do not care to speculate whether it was his initial goal) is to prove that no amount of analysis, not even more than nine hours of film, can "solve" the systematic genocide of a whole people. Those events were beyond the scope of what human beings ought to be capable of comprehending, and the massive structure of Shoah slowly moves itself to that way of thought; while the beginning of the film treats with more esoteric questions of how the Endlösung was conceived by the Nazis and understood by its victims and the surrounding communities, by the time the second half of the film is well underway, its focus has shifted to more mundane things like the internal processes of the death camps, suggesting that this, at least, is something that the human brain can wrap itself around; by the end, Lanzmann has abandoned even this focus, and more than the last hour of the film is concerned with the time before the Holocaust itself, the day-to-day functioning of the Kraków ghetto. It's as though the film and filmmaker have given up for understanding even a fraction of the thing itself; the best we can hope for, after being bombarded with inconceivable evil for hour and hours, is to maybe understand the seeds from which that evil grew.

That line of argument only really concerns the film's length - which is, indeed, the most obvious thing about the film - by suggesting that this incapacity for understanding could only be made so potent on a sufficiently vast canvas. The other part of Shoah is not its form and philosophical underpinnings, but its content; and here again, we find that 9+ hours is altogether too short a time to spend allowing the survivors of the Holocaust to tell their stories, and in this respect, such projects as Steven Spielberg's Shoah Foundation are invaluable (though he might have directed Holocaust film that was uplifting and centered on a Gentile protagonist, no-one should ever doubt that his heart is in the right place). But Lanzmann's film is a good start. The chief success of Shoah, in its hours of interviews, is to remove the Holocaust from its comfortably horrifying place in history, and restore a human face to the atrocities. It is easy to "know" that this was a terrible event with few or no equals in human existence, but there is knowing and knowing, if you follow me, and something about hearing what feel like hundreds of stories of atrocities both great and minor, spoken not by historians, nor actors reading from a well-researched screenplay, but by living men and women who witnessed those atrocities with their own eyes, perpetrated on people they knew and loved, afraid literally every day for years that it would be their turn next to die in the most inhuman place that has ever been devised, this is shattering on a level that far outstrips what most of us think we know about the Holocaust, and which belies the primitiveness of Lanzmann's stripped-down aesthetic.

Speaking laboriously through an interpreter, or in subtitled German or broken English - two languages that the director-interviewer spoke, though not as a native - most of the interviewees are kept at a sufficient intellectual remove from their memories that it is the horrifying matter of their stories and not their own distress that moves us. It is to Lanzmann's credit that only once in the film does he include footage of a survivor unable to cope with the painful memories the director is stirring up: Abraham Bomba, a barber living in the US, being interviewed in the middle of the workday, all but begs Lanzmann to stop recording as he recalls witnessing a fellow barber, forced to cut the hair of women bound for the gas chambers, seeing his wife and daughter heading of to their death. It's the one moment that I hated the filmmaker, forcing this old man to relive what was obviously a traumatic incident, and this I suppose is all the justification that he needed to do so. Rousing the strongest possible emotions in the viewer is, after all, what Shoah is designed to do.

In addition to the interviews of survivors, the film includes several far more troubling and compelling interviews with those around the Holocaust: many Poles from the cities around the camps, some of whom seem genuinely distressed by what happened and far more of whom don't seem to really care about things gone more than thirty years at the time of the earliest interviews. That even in the early '80s such easy anti-Semitism could crop in conversations about the Holocaust was one of the truly horrifying lessons of the film. But for that, nothing can top Lanzmann's secret interviews with ex-Nazis, prison camp guards and German functionaries who were processed by the legal system and found insufficiently responsible for death sentences. Something about these interviews is ethically troubling: at one point, the Treblinka guard Franz Suchomel clarifies that he doesn't want to be filmed, seemingly unaware of Lanzmann's hidden camera. This raises very real questions of privacy, questions that Lanzmann's later suggestion that ex-Nazis don't deserve privacy hardly answers, but the interviews with the Germans, Suchomel especially, are the most revealing in the film. Every one of them holds onto that mantra of being tried fairly as a talisman against any accusation of wrongdoing; even the slightest suggestion from the director that their actions were evil sends each of them into a paranoid spiral of denial. Yet each of them speaks in measured tones about atrocities that can hardly be imagined. Sometimes the subject, particularly Suchomel, will describe his role in the camp using words that can only be regarded as culpable, admitting that he does not seek and cannot receive forgiveness, but his tone is still so empty and callous that it hardly seems legitimate. They too were doubtlessly scarred by the things they did and witnessed, but their apparent lack of understanding of the moral scope of the Holocaust is disgusting to behold.

To no sane mind could Shoah possibly be called a joyful watch. It is inordinately long, and it is shockingly depressing for virtually every frame. Nor can I in good faith say that it is necessary viewing despite that; I would like to, but each viewer must decide whether or not this is something she would be willing to withstand (though I think it's likely that the people who don't think they need Shoah are the ones who need it the most). It is a vital work, and a difficult, eviscerating one. That it is one of the most important documentaries ever filmed is undeniable. Beyond that, I leave it to the conscience of the individual.