Starring: Robin Williams, Robert Sean Leonard, Ethan Hawke, Josh Charles, Gale Hansen, Dylan Kussman, Allelon Ruggiero, Kurtwood Smith, Lara Flynn Boyle.

Rated: PG -- language, subject matter, selective questioning of authority.

Nevertheless, Dead Poets Society features Robin Williams' most convincing and restrained screen work -- effectively muting his compulsion to skip from one shtick to another, rather than limit himself to playing a single character -- even though those were the very anarchic impulses that made him a unique star in the first place. And, although Williams' name appears above the title, he's not really in it very much. So, another paradox: It's Williams' best movie work because he's the least like himself and he isn't onscreen long. Consequently, he doesn't have the opportunity to rip holes in the fabric of the movie with his familiarly distracting, manic attention-grabbing tricks.

Americans have traditionally maintained a romantic, love-hate relationship with the notion of nonconformity. Deep down, we each cherish an iconoclastic image of ourselves. American movies and literature are full of rebel heroes and heroines who reinforce that image, from Melville's Bartleby the scrivener and Hawthorne's Hester Prynne to Joseph Heller's Yossarian and John Irving's T.S. Garp. At the same time (as these characters attest), we sure do resent it when other people don't behave the way we think they ought to -- that is, "like everybody else."

He's fun. He cares. He half-jokingly (but only half-) tells the boys that literature was invented to woo girls. He does quicksilver impressions of John Wayne and Marlon Brando. He stands up on his desk -- to get a different point of view on things -- and tries to get his students to follow his example. When the kids dig up Keating's old school yearbook and find that their charismatic professor used to belong to a mysterious cult called the Dead Poets Society, he lets them in on the secret: It was a group of students who met in the ancient Indian caves nearby and read poetry -- their own as well as Walt Whitman's -- thereby causing girls to swoon. Keating makes poetry attractive to these boys by presenting it as an age-old seduction technique. (Well, the impulses behind Shakespeare's sonnets weren't all chaste.) Naturally, the younger generation chooses to emulate their idol.

So, the only forces opposing Keating's philosophy are rigid and towering ones, personified by Welton's stern, rigid, downright fossilized old headmaster, Mr. Nolan (Norman Lloyd), and the cruel, stubborn parent, Mr. Perry (Kurtwood Smith, who appears to be warming up here for his portrayal of Nazi war criminal Joseph Goebbles in an upcoming TV movie). "After you've finished medical school and you're on your own you can do as you damn well please!" the ruthless Mr. Perry lectures his son, one of Keating's prized students. "But until then, you do as I tell you to!" So, who are you going to root for -- cuddly bear Robin Williams or a couple of fascistic cold fish? The deck is as stacked as it can be.

And yet, in the end, the movie indicates (despite itself) that maybe the cynic/realist from early in the picture was indeed right, after all. Although there's a carefully placed scene in which Keating tries to make the distinction between unfettered self-expression and self-destructive behavior, the principles behind the re-formation of the Dead Poets Society eventually lead to catastrophe. It becomes clear that at least some of the boys really aren't emotionally equipped to incorporate into their own lives the kind of freedom and nonconformism that Keating is selling. Now here's an idea for a movie with provocative conflicts and ambiguities -- a well-meaning, influential teacher who unintentionally becomes the catalyst for tragedy by encouraging his ill-prepared students to fly, Icarus-like, too close to the sun. But you won't find that movie here.

Luckily, director Weir does seem to have learned that the best way to use Robin Williams in a movie is ... sparingly. Either let him exhaust himself, and the audience, in an erratic flight of improvisation so that he bounces all over the place like a rapidly deflating balloon and then exits when he runs out of air; or keep him focused and down-to-earth so that he at least resembles a member of our species rather than some demented extraterrestrial mimic with a berserk radio receiver where his voice box ought to be.

For the first time since 1982's The World According to Garp, Williams plays a recognizably human character who operates within the confines of the movie rather than threatening to tear it apart from the inside to make room for his stand-up act. (The problem with Dead Poets Society is that the movie's generic strictures are too confining altogether.) Nor does he wallow embarrassingly in maudlin, Chaplinesque self-pity, begging the audience to have sympathy for poor, poor him, as he did so shamelessly in the syrupy Moscow on the Hudson and Good Morning, Vietnam.

The best thing about Williams/Keating's classroom technique is the way he analyzes his students until he can determine their needs and see through their defenses. Keating sizes up the boys' attitudes and problems and then openly teases the kids about them. In the process, he disarms them, helps defuse their hang-ups. And in these moments, we see what makes him a valuable teacher. But Keating's noble ideas about passion and beauty are stifled as much by the movie that contains him as by the school that employs him. The simpleminded, formulaic rigidity of Dead Poets Society is, in its own conservative, commercial way, almost as suffocating as the atmosphere at Welton Academy itself.