"I will imitate the natural until the becomes second nature," vows the great Shakespearean actor Edmuch Kean, having been driven mad -- or rather to an act of madness, as it were -- by members of Georgian society running about their drawing rooms, acting the parts of lovers, rivals and outraged cuckolds.

This is existenbtialism without tears, in Jean-Paul Sartre's "Kean," a ravishing farce based on a play by Kean's contemporary Alexandre Dumas pere , and given a delicious production at Arena Stage, directed by Martin Fried.Too many college versions of "No Exit" have left Sartre with a dour theatrical reputation, but this is the height of spirited wit.

As an actor, Kean is the darling of the aristocracy at play, a popular character in their little scenes of adventure. They bring these off well -- "It's so amusing to live above one's means" one says while affecting emotional excess -- but, then, they are accustomed, in official life, to performing such great roles as prince, diplomat, peer and great lady. It's not only the actor who no longer knows whether the world is a stage or the stage a world.

The title role is as multi-leveled as a staircase -- dandy, artist, drunkard, mad philosopher, wooer, comedian, tragedian, celebrity -- and Stanley Anderson dashes up and down with sure-footed speed. The only lack is demonstrated proof of Kean's legendary tragic artistry. But this would have to push through the layers of change in theatrical styles since his day, and the Shakespearean scene Sartre gives us is already hilariously over-tiered, with Kean acting Othello while faking Shaekspearean speech to cover missed lines, reacting to what is going on in the boxes and improvising a tragedy with himself as hero.

Mark Hammer, as the man who looks fondly after Kean but sometimes finds things too thick -- "Anything but your childhood," he interrupts a reminiscence; "I don't deserve that" -- is as funny in silence as with sardonic lines, and there are fine comic portraits by Richard Bauer as the Prince of Wales, Halo Wines as a grand-scale flirt, Joe Palmieri as her husband and Annalee Jefferies as a groupie.

KEAN -- At Arena through April 26.