Is rigorousness in and of itself an inherent virtue for the die-hard film geek? The set-up of Into Great Silence guarantees unusual severity: a nearly three-hour documentary about the Carthusian monks, a sect that converses once a week, on their Sunday walk, and meet just twice a year with their families. Their lives are dominated by silence and seclusion from a world that, as one monk notes, has largely abandoned God. What attraction, then, can such a film have to secular art house audiences, other than the sheer hard-assness of the proposition?

Cinematically, medieval monastaries come off as hotbeds of perversion and conspiracy when they are portrayed at all: Jacques Rivette's The Nun (with its lesbian mother abbess) and Umberto Eco's The Name Of The Rose (both in literary and cinematic form showing a monastery of power struggles, furtive gay sex and murder) are rare specimens. But with the monastic system's overwhelming power gone, so too is corruption; what's left, for the Carthusians, at least, is an austerity so pure and unambiguous that the devotion and sincerity of its members is unquestionable.

Director Philip Gröning is at least as dedicated as the monks he documents: he asked permission for the documentary in 1984, got it 16 years later, then lived with the monks for a year, filming without a crew or artificial lighting. On the one hand, the film's hushed quiet is impressive and, for at least an hour, entrancing. Traversing the four seasons and then some, the film's structure is impressionistic rather than rigorous or even noticeable. Long sequences of solitary monks cleaning out snow alternate with night masses, novices' heads being shaved, cats being fed, a herd of cows inexplicably wandering through the monastery: anything and everything, repeated and looped ad infinitum.

At first the visuals alone maintain attention, but little by little, boredom creeps in. If, as one of the masses instructs, for God there is no past or future tense -- only the present -- then the structure makes sense; for these monks, differentiation of events is unimportant. The film must travel in God's time, never building toward or leading anywhere in particular. In this sense, the film's wearing repetition is true to the monks' experience. Yet contemplated differently, it doesn't really fit. The monks never have a full night's sleep, their rest punctuated by nightly prayers; the result is a state of constant exhaustion intended to lead to heightened concentration. The film never finds its analogue; the details don't coalesce into something more definite than where Gröning began (in fact, the film's near-circular ending is its only hint at overt structure), resulting in an increasingly frustrating feeling of being tested for no apparent reason.

There is also the sense of the most interesting details being needlessly withheld. When the monks finally do get around to taking their weekly walk-and-talk, having some engagingly goofy conversations about the ethics of handwashing ("I'm not against handwashing," one observes, "I just forget to dirty my hands first"), Gröning quickly yanks us away, as if the monks' rare verbal digressions weren't as revealing of their mentality as the endless sequences of night mass. "Anyone who does not give up all he has cannot be my disciple," the occasional intertitles note no less than five times throughout the 162-minute running time, and toward the end, that seems like a warning to viewer and monk alike. Still, the seriousness of the project -- and the rare engagement of religion onscreen (as opposed to merely another attempt to exploit the evangelical market) -- deserves attention from viewers with time and sympathy to spare; hardcore formalists, however, who value structure more than a naked challenge might have a hard time keeping the faith.