The rules posted in the Cider House are like most of the rules posted in any workplace: They make no sense, but only express a distant manager's ideas of how things should be.

That, too, is the theme of "The Cider House Rules," which celebrates the practical and the compassionate as opposed to the ceremonial and the proper. It asks, what are rules for? And it finds no good answer as it follows a young man who moves into the world and discovers it too full of pain for rules.

Derived by screenwriter John Irving from novelist John Irving's book, it's a Homeric tale--literally. Homer Wells is a foundling, but he's not without a family or a destiny. His family is the kids and staff of a large Maine orphanage and home for unwed mothers in the years between the wars. He's so preternaturally well adjusted that nobody will adopt him, and so he grows up in the melancholy place as the No. 1 son of its patriarch, Dr. Wilbur Larch, and in time, himself acquires the skills of a gifted OB-GYN and pediatrician.

Tobey Maguire, in what seems to be an all-Tobey-all-the-time weekend at the movies, plays Homer to Michael Caine's flinty New English Dr. Larch. Caine is fabulous, easily the best thing in the film, with a crackly Yankee accent and a zealot's passion for practical kindness as a religion. But Maguire doesn't register nearly as forcefully as he does in "Ride With the Devil." Shorn of his Missouri accent, he's a pale, handsome youth with a kind of hypnotic passivity to him, not forceful at all, but somehow mesmerizing in his alabaster serenity.

I suppose this is good: The film is really the story of his education, so it's an account of things happening to him, rather than him happening to things. It's "David Copperfield" with a Maine accent, and it evokes Dickens's great novel so many times that you suspect it's the favorite book of Irving, and possibly even of Lasse Hallstrom, the director, a specialist in domestic drama. (His best film: the memorable "What's Eating Gilbert Grape.")

At a certain age, Homer rebels. The life that he's being prepared for--to become Dr. Larch when Dr. Larch can no longer be Dr. Larch--seems confining and the war (it's 1943 for most of the film) is raging about him, but he cannot take part because of a heart condition. He feels, as do so many young men at the tender age of 19, useless, hopeless, talentless and locked in a box already.

He hitches a ride with two near-contemporaries, an Air Corps lieutenant and his girlfriend. And what were they doing at the orphanage? The good Dr. Larch doubles as an abortionist. Lt. Wally Worthington (Paul Rudd) and his girlfriend Candy Kendall (Charlize Theron) came with a child and they leave with one--the unlettered, naive Homer. With them, Homer goes to see the world. He doesn't get far, just down the road a bit to an apple farm run by Wally's mother, where he signs up as an apple picker and takes up residence in the Cider House.

How much of the world can be crowded into a dilapidated barracks on a New England apple farm? That's the surprise of the film: quite a bit--love and death, pain, betrayal, violence, hard labor, nobility and suffering. In a few months among the apple pickers and the villagers, Homer tastes them all, even his own evil.

Basically, the movie is an almost clinical examination of parallel blasphemed relationships--joinings that the rules say shouldn't be, but which feel so damned right you cannot deny them. The first is his own with Candy--and what young man ever turned down Candy when it was offered, even if the lieutenant is off winning medals over the Burma hump. She's Charlize Theron, after all, and she's lonely, and even though they both know it's wrong, they fall together out of a loneliness that soon develops into a genuine love.

At the same time, there's the brute reality of life in the Cider House, which happens to be--given the racism of America in wartime--entirely populated by African Americans, led by Mr. Rose (the magnificent Delroy Lindo). The movie, unlike the repellent "Green Mile," sees these human beings whole, in all their complexity. Mr. Rose leads the Cider House like a magnificent warrior king, sagacious, just, brave, tender, fair, unbeatable in battle. Yet he, too, has a weakness, and that is the second parallel relationship, one so evil that it's the purest of blasphemy.

These two dramas play on the blank slate of Homer's unformed mind. How can he judge Mr. Rose while he himself is in the wrong? How can he judge Mr. Rose by "the rules" when he himself cannot obey them? The movie, at the emotional level, is Irving as distilled by Irving himself: passionately emotional, passionately real, passionate in its evocation of the complexities, not the simplicities of life.

That said, I should add two troubling notes. At another level, the movie is pure pro-choice agitprop, as it tracks Homer's conversion to the cause of choice and posits the heroism of the abortionist. Pro-lifers will hate it on that point alone, and they should be forewarned. It's also somewhat shaky in its attitude toward the war and celebrates Homer's escape from the service as a victory. I mean, this was a war with men who fed children to ovens, after all. If you didn't go fight it, you shouldn't be proud. You should be ashamed.

The Cider House Rules (129 minutes, at area theaters) is rated PG-13 for adult content, nudity and one violent death.