The Murray Louis Dance Company, which performs at the Joyce Theater through Nov. 21, has a long-established reputation. A small ensemble with a sensibly modest scale of production, it's one of the few outfits to have survived without a perils-of-Pauline history. The company has always had work; its image is of stability.
But there's something about the Murray Louis Troupe that makes one want to equate its stability, or ''survivability,'' with the capacity to plug along. Although the troupe has met success in many parts of the world, one can't help wondering if it continues to exist only because it has existed. Like the mountain, one acknowledges it because it's there - and the Louis troupe is the only dance troupe this can be said of.
For the many seasoned dance fans who live in New York, and for those who want their theater experiences to be something more than the next event on the subscription series, the Louis company is a great puzzle. They call it old-fashioned, but what they perhaps mean is middling. Louis's choreography has neither the great psychological or spiritual drive of the classic modern-dance choreographers, nor the intellectual strength of the post-modern generation. Louis's dances don't make strong statements about human nature, and they almost make statements about the nature of movement.
''Almost'' is the rub. Actually, Louis is as much a movement purist as the most fashionable of the post-moderns. Every one of his dances in the current season, from the 1974 ''Porcelain Dialogues'' to Tchaikovsky through the new ''Stravinsky Montage,'' is about the very basics of dance. How can one extend a leg in space with clarity and energy but with neither aggressive nor mushy attack? How much geometric complexity can the human body achieve without getting into a mess? These subtle questions are fascinating to the dancegoer.
The big difference between Louis and the current experimentalists is that he doesn't frame these problems with eclat. He barely lets the audience in on the questions. Sometimes, when Louis himself dances in solos such as ''Deja Vu'' and ''5 Masks,'' one can understand the point of his style through the sensitivity of his own body. Now very much the senior member of his troupe, he doesn't dance in the group works anymore, which means that their intent must explain itself in choreographic ideas rather than personal artistry.
Yet the dances keep getting made, and with each premiere the need for justification grows more urgent.