Not quite prime-time lawyer; 'MILLER'S COURT' MIXES LAW WITH SHOWBIZ

Arthur Miller, a Harvard law professor and a fast-rising media darling, is helping himself to another slice of mushroom quiche. It is Tuesday evening at Channel 5 studios (WCVB-TV), the usual night for the taping of ''Miller's Court, '' a Boston television show in which the audience matches wits with the flamboyant Miller on controversial issues of the law.

Miller, the star, is trying to make small talk with his guests: Nancy Gertner , a local lawyer well acquainted with feminist legal issues, and Phyllis Schlafly, also a lawyer and founder of the controversial and conservatively inclined Stop-ERA and the Eagle Forum.

Mrs. Schlafly, dressed in red, white, and blue Ultra-suede, is proving intractable. In the remains of a rapid-fire Brooklyn accent, which somewhat belies his three-piece-suited appearance, Miller tries to be soothing, if not outright ingratiating. ''The show rarely gets out of control,'' he says, though the format is known for its unpredictable and sometimes volatile moments. Mrs. Schlafly barely nods in acknowledgment. So much for small talk. The conservative lawyer, one of tonight's two ''experts,'' is soon whisked away for makeup and a quick review of tapes of past shows.

Miller and his small entourage of researcher, producer, and assistant, are left to their own devices, which at this moment turns out to be chocolate mousse pie and ice cream. ''I'm here to bring the law to the media,'' he says between bites. ''There's traditionally been very poor communication between the two. Or, if you're into cliches, I'm here to demystify the law.''

Whatever his reason for being here, the colorful and uninhibited Miller, one of the most theatrical and popular professors at Harvard Law School, is now captivating television audiences as well. In its third season, ''Miller's Court'' has moved beyond its original Boston audience. The show has been sold to public television, which is marketing it through 50 separate stations. Miller also appears weekly on ''Good Morning America'' and on the local news here to discuss points of law that are ''sometimes consumer oriented, sometimes whimsical,'' he explains.

Another series of legal-issue shows for and about juveniles has already been taped and is awaiting release sometime in January. And the inevitable book, ''Miller's Court,'' is about to come out as well. Somewhere in between, Miller also manages to lecture, consult, write legal articles, and compile textbooks. ''I'm a workaholic,'' he says with a shrug.

If there is any unifying thread running through all the breakneck-paced activities, it is ''that having a good time is not inconsistent with learning.'' Already appreciated for his costumed theatrics during his Harvard lectures, Miller continues to cavort on television. Indeed, any five minutes of any show indicates that he is no stranger to clowning. ''Keep in mind this is always a game,'' he admonishes the audience before the cameras start to roll. ''We're here to have fun and to learn something.''

Just how that learning takes place is something else again. For Miller is also no stranger to friendly goading and needling, or any other tactic likely to draw impassioned protests from the audience. Relishing the Socratic method, the lawyer-performer relishes eliciting responses from audience participants and then watching them contradict themselves as he drives a point home. Confides one audience member, ''Miller drives me crazy,'' a comment the professor no doubt would warm to. ''I push,'' Miller says. ''But people don't understand they have the capacity within themselves to understand the law.''

Understanding the law seems to be what Miller is all about, whether he is on television, in class, or on paper. ''The game here is to make people understand that the law is not an abstraction or capricious,'' he explains later in his book-lined, carpeted Harvard office. ''I want people to see that the law is nothing more than a balancing of competing laws and ethics - that the law changes as society changes.'' As he says, nothing pleases him more than the comment, ''You made me think about an issue that I thought I had formed a judgment on.''

So on come the laymen to duel with him in his legal forum. And a real slice of Americana they are: black, white, young, old, policemen, homemakers, grandparents, and feminists, all wearing large yellow name tags and all jammed into the studio lounge to relax, get acquainted, and eat a good quantity of vanilla-cream cookies and apple cider before the rigors of the show set in. Says Miller, ''We want the energy level up, up.''

What Miller also wants up, up, is the audience tendency to jump down each other's throats at the slightest disagreement. ''Be like cats ready to pounce,'' he encourages them. ''Don't raise your hands, just start talking.''

On this particular show, entitled ''Women's rights, or Should the ERA be ratified?'' there is no problem getting the audience sufficiently snarly to provide good theater for the folks at home. Even such gentle senior citizens as Isaac, Flo, and Dorothy, from the foster grandparent program, are good catalysts for disagreement.

''Isaac, what do you think - should women be drafted?'' Miller throws out the question like bait. Isaac, a good-natured bear of a man, rumbles out a reply. Not controversial enough. One can see the wheels turn in Miller's head. Quickly he wheels and throws out another. ''What about combat?'' Phyllis Schlafly doesn't bat an eye before jumping into the fray. ''Isaac, the purpose of the draft isn't to die for your country,'' she intones, '' but to make the enemy die for his, and men can do that better than women.'' Miller, never one to hesitate himself, adds further fuel to the fire by referring back to an earlier speaker: ''Agnes, she's saying your position makes women second-class citizens.'' He cocks his head for the expected sputtered response. ''No, no, women serve at home,'' defends Agnes, who sports the Eagle Forum's gold-tone eagle pin on the collar of her high-necked blouse. The debate, as anticipated, is off and running. Only the producer, sequestered back in the control room, holds her hands to her ears and squeals, ''Oy, oy,'' to the building -cacophony on stage.

One of the compromises Miller acknowledges must be made is between the ''noise'' level of the fired-up audience and the conveying of legal reasoning. ''The more noise there is, the less information that is communicated,'' Miller admits, a problem that is forcing the show into less audience participation and more debate with the experts. Producers are also considering moving the half-hour format out of the studio and into a series of on-site locations - a move they say should lend additional realism to the weekly debates.

Another problem recognized by audience members and Miller himself is the question of the show's actual depth and breadth. Says one audience participant: ''I get frustrated watching it. He's putting on a show - just skimming the surface. He never really gets into it (the issue).''

Much of the trouble seems to lie in the differing expectations that arise between the ''live'' version and the televised show. Miller explains: ''The show isn't made for those 50 people there in the studio. I have to go with what information is comprehensible in 21/2 minutes. You and I know what's missing, what didn't get on. But the standard has to be what is included in those final 22 minutes (that get on the air). And I think that that is better than the 'Dukes of Hazzard.' ''

Whittling down complex legal principles to what is comprehensible to laymen in 21/2 minutes seems almost ludicrous - especially for an intense, intelligent man who has spent years at Harvard, both as a student and now as a professor, and is a nationally known privacy and copyright expert. ''I admit this media thing has really come out of left field for me,'' he says by way of explanation. ''Very few academics are interested in the media. But I've always been kind of schizoid, living my life like a juggler - constantly moving away from that which is boring.''

That which is boring hardly seems like a problem for Miller. As he says, ''I never take vacations.'' Nor can he seem to separate his ''fun time from the professional time.'' Well, there are exceptions to every rule: ''I will work up to, but not including, the Ohio State-Michigan game,'' he hollers out to his secretary. There are also some model trains atop a nearby bookcase. ''Oh, those are my hobby,'' he adds without a trace of sheepishness. ''I have friends that come over and play with them at my house.''

Sitting here in his office with its handmade ''Good Miller America'' poster plastered across the door, it is not difficult to see the man has a sense of humor. What is also easily detectable is his commitment to the law and what it stands for. ''I love this profession,'' he says. I think it has enormous potential for helping society far beyond the individual.''