There is nothing solid to suggest that Father Flynn is doing anything inappropriate, but there's a mound of circumstantial evidence. Believing herself to have been around the block enough times to smell a rat, Sister Aloysuis begins a campaign to bring the priest down. Father Flynn repeatedly denies any wrongdoing, but his principal is convinced that she is right and, frighteningly, believes that her certainty is proof enough. Sister James, on the other hand, isn't so sure.

Doubt began life as a stage play and you can tell that from watching the film. There's not a whole lot of room to open this story up; it's essentially a bunch of people standing around talking. However, what they say is so compelling - and the performances are so authentic - that you soon forget the staginess and become completely involved in the story.

We all know someone like Sister Aloysuis, and Meryl Streep nails that kind of self-righteous superiority. Believing herself to be a master people-reader, she completely closes herself off to the possibility that she might be wrong. Streep really anchors the film because she imbues her character with just the right touch of ambiguity; on one hand, we feel she's making a snap judgment, yet on the other hand, her certainty is so forceful that it carries influence. Just look at the way she impacts Sister James, who doubts Father Flynn's guilt in her heart yet is so compelled by Sister Aloysuis' righteousness that it makes her question her own beliefs.

The really great thing about Doubt is that it never comes down on one side or another. What Father Flynn did - or did not - do is never revealed. In fact, it's not even important. This is not a story about whether a priest molested a young boy; it is about the discrepancy between what we "know" and what is actually true. There are so many ways the tale parallels real life. I could sit here all day and list people who base their actions (oftentimes hateful or antagonistic) on their own personal certainty. Shanley suggests, however, that "knowing" is not the same as knowing. In other words, being sure of something does not necessarily make it so.

If you like those kinds of hypothetical, debate-fueling ideas, then Doubt is one of the year's must-see movies. As you watch, you will find yourself having an inner debate about the scenario. Yes, Father Flynn's actions are suspect, and yet he has a perfectly reasonable explanation for all of them. Is he guilty? Has he done something wrong? Do you have doubt? I love movies that twist your thinking like this.

While the text was already there, the casting has changed during the journey from the stage to the screen, with major movie stars inhabiting the roles. (Cherry Jones originated the role of Sister Aloysius onstage.) Despite the shift, it all still works because everyone is so good. Amy Adams again demonstrates her ability to get under the skin of the characters she plays. Sister James represents the audience: we don't know who to believe, and our opinion, like hers, wavers back and forth. Phillip Seymour Hoffman matches Streep's intensity as Father Flynn. He argues his innocence with the same fervor with which Sister Aloysius argues his guilt. Watching these two powerhouse actors go at it is a real thrill. Then there's Viola Davis, who has a supporting role as Donald Miller's mother. She shares a dynamic scene with Streep in which the nun informs Mrs. Miller about her suspicions, only to receive a very surprising response.

Doubt is exceptionally well written and acted, and the technical credits (cinematography, music, editing, etc.) also combine to make a Catholic school in the 1960's as much as character as any of the humans. When it's over, you walk away wanting to talk about and debate what you have seen. I'm not sure I've ever seen a movie explore the idea of a "gray area" better than this one.

( out of four)

Doubt is rated PG-13 for thematic material. The running time is 1 hour and 44 minutes.