For one who has made an emperor's fortune directing plays and films, won six Tony awards and an Oscar, and generally enjoys the reputation of being the ultimate Mr. Fixit of the theater, the simile is humble indeed.

"Directing," says Mike Nichols, "is like cleaning a floor. You clean one square, then the next one, and the next one, and finally the whole floor is clean. Then you decide if you want to change its color or give it another coat of polish. I don't know any other way to do it. There is no magic stroke that makes a play work."

You expected, maybe, a secret formula?

In a world of self-inflated artists, drunk on the agony and inspiration of their calling, Nichols would just as soon be viewed as a common laborer. "It seems to me that thinking of oneself as an artist was used up long ago by embarrassing people in Hollywood," he says. "You end up saying, 'Listen, I'm just trying to make a living. Leave me alone.' Privately, you may think something else. But publicly, you stay away from all that."

From the start of his career as half of Nichols and May, the celebrated improvisational comedy team of the '50s and early '60s, Nichols has had an unerring eye for the ridiculous. That eye is currently fixed on "Social Security," Andrew Bergman's pre-Broadway comedy about an upwardly mobile married couple whose trendy Manhattan life style is disrupted when the wife's mother is unceremoniously dumped on their apartment doorstep.

Local reaction has been mixed. No one's denying that "Social Security" is indecently funny in spots. But the play, which winds up its tryout at the National Theatre tomorrow night, has struck some as being fairly ephemeral and, considering its 90-minute running time, over almost before it begins.

"I don't want to be in the position of defending 'Social Security,' " Nichols says. "My commitment to it is obvious: I chose to direct it. I think it's very funny. Making people laugh is a perfectly honorable thing to do -- for which critics are always beating the crap out of writers."

Nichols rarely talks to the press. He doesn't particularly enjoy it, and he needs the publicity about as much as Elizabeth Taylor. Still he is being game this afternoon -- suffering questions with a quiet charm that seems compounded in equal parts of boyish modesty and adult wariness. When he was younger, he had an appealingly goofy look -- mitigated, now that he is 54, by his immaculately tailored wardrobe and the sobering suggestion of middle-aged jowls. His posture is sedate and he speaks in the carefully measured rhythms of an investment banker. It is only when he laughs -- a sudden disruptive cackle -- that the carefully composed facade tends to crack and you remember him, not so long ago, perched on stage on a bar stool, improvising mad routines about guilt and neurosis.

Nichols can do pretty much whatever he wants these days. Broadway is beholden to him not only for directing "Hurlyburly" and "The Real Thing" at a time when the straight play has all but vanished from view, but also for bringing Whoopi Goldberg to the public eye by presenting her one-woman show last season. When it looked as if no one else would produce "Annie," he volunteered for the job. ("I just thought it was nice and I wanted people to get a chance to see it," he says. As for rumors that he had a fine hand in its making? "Very fine, if at all. All I did was say things like 'You have to go faster here.' ")

His movie career, which began on a spectacularly successful note with "The Graduate" and "Who's Afraid of Virginia Woolf?," went into a slump in the 1970s with such films as "The Fortune" and "The Day of the Dolphin." Three years ago, "Silkwood" kicked it back into high gear and trade gossip has it that his latest film, "Heartburn," based on Nora Ephron's best-selling roman a' divorce, will be the succe's d'estime of the summer.

"It's always seemed to me that you should be able to do this, and then that. Or this and that at the same time," Nichols says. "I suppose for the moment, it looks as though I have carte blanche. But as soon as you say that, it isn't true anymore. It's a useless concept anyway. We all work out of limitations -- personal and technical. In movies, the medium is money, which is an automatic limitation. In the theater, you have to please an awful lot of people just to keep your head above water, which is also the politician's limitation.

"But I can't tell you a whole lot about my selection of material. I don't understand it myself. I know there are fewer and fewer things I want to do. Like 'Heartburn.' I didn't trust it until we were five, 10 days into shooting. Then it became clear to me that it was at least alive. I think maybe my subject is the relationships between men and women -- without much of anything else. I'm interested in things that happen to men and women, centered around a bed. That seems to be a theme. But I don't know how to narrow it down any more. Orson Welles once said to me, 'Don't worry about that stuff. All we have to do is do it. Let the others figure it out.' "

He sits pensively for a moment, then adds, "I do think the world has changed and I have changed with it. My initial impulse in work was to prove what fools we mortals were. And now I believe there's hope for people -- with each other -- and that if you don't move toward generosity and love, you die. I mean that quite literally. It's the only way to grow and continue. If you don't treat yourself and others with some decency, you die.

"More and more I'm finding, both in life and art, the secret at the core of things is that women are more generous than men. They have a network of support that men don't have. They're more for one another than men are. Men keep beating up on women in various ways, and the women keep responding with life-giving things . . . if that doesn't appear hopelessly sentimental."

He obviously think it does, because he squirms ever so slightly, and straightens an elegantly striped tie that is already hanging perfectly straight.

Born Michael Igor Peschkowsky in Berlin (German is his first language), Nichols has long since exorcised what he once described as a checkered childhood, marked by the conviction that he was a strange and solitary creature. His father, a Russian physician, had fled the 1917 revolution, then in 1939 fled Berlin for New York, sending for Nichols and his younger brother shortly thereafter. When their ailing mother was able to join the family, Nichols had already been packed off to boarding school. His father's subsequent death from leukemia only compounded an adolescence rendered difficult by a lack of money, Nichols' self-admitted tendencies to be "a fresh, little kid" and his decidedly curious appearance. (At the age of 4, all the hair on his head dropped out in a rare reaction to a shot for whooping cough.)

He was an elfin-looking, vaguely undirected student just out of the University of Chicago when he met Elaine May, the first of the two women, he says, who have had a profound influence on his career. "Elaine woke me up to begin with and made me realize there were things I could do I hadn't known about," he says. Their irreverent act, which went quickly from the relative anonymity of Chicago clubs to Broadway and national television, was dissolved in 1962. It was not without some bitterness and pain, both of which seem to have healed with time. In 1963, he directed his first production, Neil Simon's "Barefoot in the Park," won his first Tony and found his life's calling. "As it turned out," he says, "everything I had randomly done up to that point -- being an entertainer, working in clubs -- had been unconscious training for my real work, which is directing."

These days Nichols and May look in on one another's projects, swap advice and lend a helping hand. "Elaine always has one or two things to say," he explains. "It will be something very practical, like 'I didn't know the characters were in New York.' But it will change everything."

The other life-giver is actress Meryl Streep, who roused Nichols from the professional somnolence that overtook him in the late 1970s. He was by then a noted director, but "I'd lost a lot of the pleasure of directing. Nor was I very good for a while. I get tired of things. I wear them out. It's always been true of me. And I sort of went to sleep. Meryl woke me up. This time, I feel -- knock on wood -- I'll remain awake."

Directing Streep in "Silkwood" and most recently in "Heartburn," Nichols found her talent awesome, her instincts unfailing, her willingness to take risks invigorating. Streep, in fact, is one subject on which he apparently does not feel obliged to weigh his words.

"She's an actual great actress," he says, picking up the pace. "Nobody but Peter Sellers and Alec Guinness have tried to do what she's doing in films. Women have never been allowed to. They're supposed to be the same person every time, or people get mad. Meryl dares to be different in every movie. Her aim is to be somebody else. In 'Heartburn,' she's not playing Nora Ephron, and the film is not the story of Nora Ephron and Carl Bernstein. But just as an extra kind of flip, she is Nora. I mean, she has mannerisms of Nora's that you've never even noticed. It just shakes you to the marrow."

Nichols is sky high on "Heartburn" at the moment. "I really feel I was changed by the movie," he says. "For all of us, it was this lifetime experience -- something none of us had ever had before or will again. I mean, 120 people fell in love with a film. Everybody wept the last few days. That doesn't necessarily have anything to do with the quality of the picture. People have hated each other and fought all the way through a film and produced a classic.

"But at a certain point, all these things started to happen that no one had planned -- everyone would suddenly discover what the scene was about, the actors would instinctively sense what was happening to one another, I'd discover the right viewpoint for the camera. It really was a miracle.

"Making a movie is starting a snowball rolling. After a week or so you can't stop it. All you can hope is that it is rolling in the right direction. There's no going back. Whatever you learn about a scene, you've learned too late. You did that scene yesterday. So everyone, including the director, has the feeling that something is happening which is vaguely out of control.

"This is embarrassingly semi-mystical, but you have to have the sense not to try to control it. Starting with 'Silkwood,' when I began working with Meryl, I've become aware that giving up control is the secret, maybe, of happiness altogether. Our experience on the picture was that the scenes really decided themselves. If nobody is saying, 'Here's what I want you to do,' and if the actors are good enough, something really begins to happen: life occurs."

Nichols' visible enthusiasm for "Heartburn" and his relative reluctance to talk about "Social Security" do not necessarily signal that his allegiances are shifting to the cinema. He just finds it easier to speak about the project he's not actively involved in at the time. "I feel like it's tempting the devil to admit, defend or in any way consider the value of a play I'm still working on," he says. "We're right in the middle of 'Social Security.' It's a soft-shell crab on the way to forming its shell. You really can't start putting up your finger, every other minute, to test the wind.

"You know Elaine once went to see a play of hers," he says. "And the people who were doing it said, 'Gee, we wish you'd come a little later, because we don't know all our lines and the doors don't work.' And she said, 'Give me a break. I'm a professional.' So she watched the rehearsal. Afterwards they said, 'What do you think?' And she said, 'Well, you don't know your lines and the doors don't work.'"

He chuckles at the unstated moral, which apparently is that -- in play production, as in life -- you take one step at a time.

Nichols may be one of the kings of Broadway, but he is philosophical about the shrinking of the once-fabled realm. "Everyone's tired of the whole process," he says. "Everyone's tired of spending $150, once again, to be misled into seeing something that bores [them] for three or four hours. That was one of the reasons I was drawn to doing a comedy that doesn't assault you for hours and pin you down. If Broadway has to go, it has to go. It just means that Broadway will rise in another shape. What is Broadway anyway? It's just some Shubert houses.

"There will be a phoenix somewhere else. There's almost no city, including New York, where you can't see extraordinary living things. 'Aunt Dan and Lemon' [at the Public Theatre] was as exciting and remarkable as anything in 20 years. Long ago, I said I'd rather do a play than see one. That's still true. But you give me Wally Shawn's play and I'm happy with the theater for a year.

"What is too bad about Broadway is that when something does come along -- like 'Glengarry Glen Ross' -- it stays there for maybe less than a year. That whole thing was as close to a perfect evening as you can get -- perfect play, perfect production, I was perfectly happy. Then it's gone and it's like it never happened. But I suppose there's something happening everywhere that people aren't noticing. They stay home in every way."

He shrugs. His instincts tell him he's on the right track with "Social Security," and his instincts haven't often betrayed him. Audiences are laughing like crazy.

"But I think there's some meaning in it, too," he says, "although that's flattened out right now by all the laughs. It's about being freed of the family rigmarole. It's about not denying your roots. It's the story of some people, who have turned their backs on their past, who are threatened by it, and are forced to confront it in the person of a highly guilt-provoking and unhappy mother. By not shoving her under the rug, by embracing her -- even through gritted teeth -- they free themselves and they free her to start a life of her own, which is all anybody wants for his parents. They have therefore taken a step forward and are not so pretentious as they were at the beginning of the play.

"I'm not saying that's a lot. But I'm saying that's what happens. And it seems to me we have a chance of making it manifest so that audiences feel something has taken place. As for the 90 minutes, well, I didn't choose the play because of that. But if you tell me I'll be in and out of a theater in an hour and a half, I'm much more likely to go. Most plays these days go on until there's no place to eat."

Furthermore, he's got three weeks of New York previews ahead of him, before facing the critical fraternity. Bergman's beavering away on rewrites. The actors are enthusiastic.

* "You know, the best actors are those who love acting -- and they know they love it, which is the most liberating thing of all," he says. "They're rid of all this crap about how painful and difficult it is. So they're free to go a lot of different places -- literally, physically, metaphorically. It's like what [novelist] Milan Kundera said of his characters. They're sent to him across borders that he can't cross himself, into places he would like to go. They allow him to have experiences that are unavailable to him in life or might destroy him."

He pats his tie again. "Well, that's true of a director, too. Not only do you get to go on the journey, but you get to choose when you are going, what you'll visit, who'll be along and when you'll get there. It's ordering things the way you can't ever order them in real life, making things turn out the way you'd like them to turn out."

The unflappable Mike Nichols, cool as his crisp white shirt, gives off no signs that "Social Security" isn't going to turn out just dandy.