Ah, Freud's Vienna! Repressed sexuality, labyrinthine guilt, balletic hypocrisy! No, not at all. In the contemporaneous Vienna of "Undiscovered Country" at Arena Stage, the slightest flirtatious whims are consummated immediately. Everyone, including the lovers' spouses, knows exactly who is sleeping with whom, and concessions to the polite forms of discretion are minimal, because no one much cares. The enemy isn't guilt, but boredom. For all the lavish costumes and elaborate manners, this is a remarkably familiar world of selfish and dissatisfied swingers. The only tragedy of what passes for love is that the feeling is so fleeting. Given absolutely free range, in a world of comfort and leisure, the soul cannot even amuse itself. There is a testimony to the psychological validity, if one is needed, in a mash note to the author from Freud, reproduced in the program. For an act of murder, as much as for a sexual liaison, the only motivation is "Why? Because I felt like it." The play, a 1979 Tom Stoppard adaptation of a 1911 play by Arthur Schnitzler, is fascinating theatrically as well as psychologically, with its stylistic overlay of bedroom farce sparkling on top of that undiscovered territory, and one that shows off the versatile Arena company particularly well. The production, directed by Garland Wright, maintains a light charm when hovering over the dark abysses. Richard Bauer, as chief protagonist and pleasure-seeker, is a triumphant embodiment of the attraction of pure amorality, and Stanley Anderson engagingly Chekovian as the one person with a touch of yearning for moral order. Barbara Andres and Julie Osburn, in different ways, convey both the beauty and the pathos of women in whom the ability to function smoothly in this cynical world has become clogged by sentimentality. And Mikel Lambert, Mark Hammer, John Madden Towey and Kevin Donovan are among those who have filled out this circle with quick comic characterizations. UNDISCOVERED COUNTRY -- At Arena Stage through April 18.