There are few more dramatic subjects than a union of two people from opposite backgrounds. Witness the wide appeal of "Othello," South Pacific," "The Odd Couple" and "Children of a Lesser God," which opened at the National Theatre last night.

This is one of those rare plays (and they're getting rarer) with the capacity to fuel argument. It asks good questions: Where does understanding leave off and pity begin? When does the drive for independence become an expression of perversity rather than strength? Does the struggle to overcome a handicap mean admitting one's inferiority? Is there something wrong with that?

But the questions are compelling only because they arise from a compelling story -- a love story of two people made to bait each other. James Leeds, played by Peter Evans, is a nervously light-hearted young teacher of the deaf. In his Peace Corps days he helped introduce Brussels sprouts to Ecuador, and he continues to enjoy a challenge. His latest challenge is Sarah Norman, played by Linda Bove, a smart and attractive deaf woman who refuses, on principle, to lean lip-reading or spoken English. "I don't do things I can't do well," she explains. She has virtually given up on hearing people (including her mother), and works as a maid at a school that have virtually given up on her.

At first James tries to joke his way past Sarah's defenses. She is dealing with the man who "saved Ecuador," he tells her. She tells him his jokes aren't funny in sign language, and his signing is so slow it's boring." (She can sign faster than he can talk, it turns out.) Several balky classes later, he invited her out to an Italian restaurant, where he interprets veal picatta as "cow baby sauteed in lemon and butter," and their relationship turns abruptly romantic.

The play was based, partly, on the marriage of actress Phyllis Frelich and designer Bob Steinberg. It came to be written after they met playwright Mark Medoff at a theater workshop at the University of Rhode Island, and Frelich told Medoff there were no roles for her in the "hearing theater." Medoff proceeded to shape a play that not only answers her complaint (Frelich is still acting the role on Broadway), but can be followed by deaf and hearing audiences at the same time -- since the leading actor (John Rubinstein, originally) translates the sign language into speech and the speech into sign language, sometimes for several characters at once.

James and Sarah are demanding roles, and Evans and Bove meet the demands. Like Rubinstein, Evans, who played the young reporter in Tom Stoppard's "Night and Day," succeeds in blending his occasionally artificial duties as interpreter into a smooth and persuasive performance. Bove, a nine-year veteran of the National Theatre of the Deaf and more widely visible as the sign-language interpreter on TV's "Sesame Street," seems younger than Frelich and a shade less harsh, but at no cost to the fierce integrity of her character. Just as important as these individual strengths, Evans and Bove are convincing and involving as a couple.

The script clearly calls for a stylized staging, and that's what Gordon Davidson has given it. Several modular units of wooden benches (with a suitably institutional look) shift and slide about the suggest a variety of locations. The scenes begin and end without any formal declaration to that effect. Sometimes the actors remain on stage between scenes and do more than pause momentarily to convey substantial shifts of time and place. In other productions, this sort of direction has often been a tip-off to pretentious writing and acting, but "Children of a Lesser God" offers reassuring evidence that it needn't be so. And Evans and Bove, perhaps even more than Rubinstein and Frelich, keep things going so fast that few people are likely to complain about the inevitable repetitions as dialogue is translated from one language to another.

The pace of this production is "full speed ahead" virtually from curtain to curtain. So much so, in fact, that it is easy to miss bits of dialogue and, in the process, some of the issues that divide James and Sarah. But there is an abundance of issues to choose from.

Sarah's refusal to lean lip-reading is a gesture of independence. Yet it has the ironic effect of making her more dependent on James. He becomes a constant interpreter for her, as he is for the audience. "My hands are all worn out," he says after a four-way conversation over a job-discrimination complaint she is filing. From time to time, he gets so exhausted that he leaves something untranslated, explaining it was "nothing important." When he says this, Sarah is, naturally, annoyed. A small annoyance in the hearing world; a huge annoyance in the deaf world. We can understand how she feels. Up to a point.

CHILDREN OF A LESSER GOD by Mark Medoff; directed by Gordon Davidson; set by David Jenkins; costumes by Nancy Potts; lighting by Tharon Musser; with Peter Evans, Linda Bove, Deanna Dunagan, Nanci J. Kendall, Richard Kendall, Ken Letner and Stania Lowe.

At the National Theatre through May 9.