As an actor, Richard Bauer has been known to go to physical excesses, which really makes him the perfect choice for the title role in Arena Stage's superlative revival of "The Imaginary Invalid." For what is Argan, the first of the truly great pill-poppers, if not a man acutely in touch with every palpitation, shudder, burp, twitch and gas pain in his body. This hulking high-chair cry baby won't be happy until he occupies all the beds in the hospital, preferably simultaneously.

Bauer, who can collapse like a deck chair, talk with or without teeth, emit a wheeze that sounds like the wind off the Sahara, run at the nose (and after the maid), and seemingly touch his shoulders to his ears, has all the proper skills for the role. Yes, it's a wildly baroque performance he is giving, but Argan doesn't just have a headache. He's got a 24-hour-hang-the-family-don't-talk-reason-to-me obsession: He thinks he's deeply ill and is ready to marry his daughter to a perfect boob of a doctor in order to have free medical advice around the house.

It is common to view "The Imaginary Invalid" as an attack on the idiocies of 17th-century medicine. But that's not the half of it. Like all of Molie re's plays, this one is about the despotism of the single-minded and the extraordinary lengths rational men must go to right the balance. Indeed, Arena has restored the final masquerade, normally amputated from performances of the play. In a delirious ceremony of mock Latin and academic gibberish, Argan is crowned a doctor by the other characters, disguised as pedants and quacks. After all, if he's going to demand round-the-clock ministrations, who better to minister than himself? Physician, cure thyself!

But most of all, Molie re's plays are wondrous pieces of comic machinery, in which acting and acrobatics join hands, and the sheer joy of performing is as immediate as the hullabaloo in the marketplace. Garland Wright's direction is enormously sophisticated, but not so sophisticated that it overlooks all the exuberance of traveling players blowing into town. What Wright and set designer John Arnone have devised is a series of stages within the Kreeger stage that suggests the curtained-off areas in a large ward. As the self-propelled curtains open and close, the acting space is constantly redefined and one begins to suspect the presence, not of stagehands, but of an industrious team of invisible nurses on their early morning rounds.

In this tight, white world, the extravagantly costumed actors stand out like Mardi Gras celebrants against a snowbank. While Wright never forgets that all of them--stepmother, daughters, swains, apothecaries and sawbones--are involved in petulant plots and counterplots, the staging also has the abstract grace of dance. It is earthy and ethereal at one and the same time, a marriage I have not seen pulled off quite so successfully since Peter Brook's production of "A Midsummer Night's Dream."

The Arena cast gleams like a scalpel and cuts . . . right to the funny bone. Escalating tics to traumas, Bauer is an extraordinary presence for other actors to play off. And play the others do. Halo Wines is a triumphantly wicked stepmother, her skin as gray as an old bed sheet but the envy in her heart as red as the large ruby dancing on her bosom. Christina Moore's maid constitutes a veritable flying dervish of mischief, while Marilyn Caskey, as the marriageable daughter, conducts herself rather like Goldie Hawn at the Court of Louis XIV.

Yeardley Smith, playing Argan's youngest daughter, brings sweet looks and a murderous rage to the state of childhood, while Dan Desmond brings slick duplicity to the profession of notary. Then there is that virtual parade of imbeciles in flowing black robes and pointy hats, the men of learning who devise the enemas and prescribe the potions that have brought Argan so low. Henry Strozier, Kevin Donovan, J. Fred Shiffman and Joe Palmieri act them with an inflated sense of pomp that leaves the ridiculous far behind for the out-and-out surrealistic.

Yet, all is not madness and merriment. Urged at one point by his brother to give up his absurd medications, Argan rolls himself into a frightened ball and whimpers desperately, "I can't, I can't." In Bauer's interpretation, the line is more than the helpless wail of the addict. It is also the cry of all failing men before death's dark specter.

THE IMAGINARY INVALID. By Molie re. Translated by John Wood. Directed by Garland Wright; sets, John Arnone; costumes, Ann Hould-Ward; lighting, Hugh Lester; music, Marc Antoine Charpentier. With Richard Bauer, Christina Moore, Marilyn Caskey, Halo Wines, Dan Desmond, Charles Janasz, Henry Strozier, Kevin Donovan, Joe Palmieri, Yeardley Smith. At the Kreeger Theater through March 6.