LEE STRASBERG, the director and acting teacher who died of a heart attack last week at the age of 80, personified a school of teaching that is nearly as controversial now as it was 50 years ago when he began exploring it. He had a major influence on the style and direction of American theater and film in the 1940s, '50s and '60s and counted among his students some of the biggest names in the profession.

"He was the father of us all," said director Alan Schneider, a longtime member of the Actors Studio, which Strasberg headed for three decades. "I loved him and I hated him, but there is no question that he was the father of a whole generation in the American theater, and there is hardly an actor working in film today who is not indebted to Lee."

He was as complex and full of contradictions as the craft of acting itself; a man who focused his actors on feelings yet in many ways repressed his own; a man who became identified--through students like James Dean and Marlon Brando--with the so-called "torn T-shirt," mumble-mouthed school of performing; a man who had one of the best collections of theater books in the country, and had an intense, wide-ranging and scholarly intellect. The exercises introduced by Strasberg and other American disciples of the great Russian director and teacher Constantin Stanislavsky, and his student Richard Boleslavsky, have become part of the lexicon of acting training, character preparation and performance. The development of realism, in all aspects of theater, was affected greatly by Strasberg's teaching and the ripples of influence from his students, friends, and associates. The first major flowering of the Stanislavsky techniques in this country took place in the Group Theatre, founded by Strasberg, Cheryl Crawford and the late Harold Clurman in 1930. The Group, operating on shoestring budgets and performing in lofts, brought a new social consciousness to the American stage, with such landmark productions as "Awake and Sing" and "Waiting for Lefty" by Clifford Odets and Sidney Kingsley's "Dead End." Actors who appeared in those productions included Lee J. Cobb, Franchot Tone, John Garfield, Elia Kazan and Stella Adler, whose feudwith Strasberg over interpreting Stanislavsky lasted until his death.

Strasberg's students read like a roster of Who's Who in show business: Paul Newman, Joanne Woodward, Marilyn Monroe, Ellen Burstyn, Al Pacino, Robert De Niro, Eva Marie Saint, Mildred Dunnock, Rod Steiger, Jane Fonda, Sally Field, Ben Gazzara, Celeste Holm, Franchot Tone, Patricia Neal . . . They won awards by the bucketful and most speak reverently of their teacher. In later years, he also coached sports stars interested in acting, such as O.J. Simpson and Bucky Dent.

The "Method," as the Stanislavksy approach was dubbed, has been parodied, ridiculed and dismissed, but rarely understood. How can pretending to be a tree help an actor portray Andrew Undershaft in "Major Barbara"? What does your memory of how you felt when your dog died have to do with a character's feelings in a play? Isn't being heard in the last row at least as important as knowing what the character's mother was like? The controversies implicit in these exercises have long been hotly debated, although many of the techniques are now standard in acting courses across the country.

Strasberg thought that Laurence Olivier wasn't much of actor; that Eleonora Duse would have been severely criticized in one of his classes. It was said that no one was admitted to the Actors Studio on the first audition, and Strasberg's angry, withering criticism burned indelibly in a student's consciousness.

". . . To suffer his wrath, whether it be a masked stoical iciness or a shrill, maniacally enraged outburst, was each actor's nightmare; to be approved by him, the dream. The limitless power vested in him by these actors for their spiritual life or death was awesome," wrote Margaret Brenman-Gibson of Strasberg in her comprehensive biography of Clifford Odets, the playwright who worked with Strasberg in the formative years of the influential Group Theatre. Strasberg said later he gave up these furies because they prevented actors from understanding what he was trying to say, but added, "To tell you the truth, we sometimes miss these outbursts. I think they often helped us in the work."

"I have received good reviews and they don't make me feel as good as a word of praise from Lee," said Saint in a telephone interview the day after Strasberg died. "He was like a father and a psychiatrist. We wanted to please him because we knew he was a great teacher."

"Lee can be as close to actors as a psychoanalyst and as distant as a god," playwright Sidney Kingsley once said.

One of his major messages as a teacher was the development of a discipline; he believed, like Stanislavsky, that the actor's body is his instrument and regular exercises--physical, vocal, emotional--are essential for virtuosity. "What he imbued in us was a work ethic," said Eli Wallach, who was a charter member of the Actors Studio and a friend of Strasberg. "The mass media makes you lazy; a television series is like a roller coaster. When you get out in the jungle of the commercial theater world you make compromises. He taught us a way of constantly challenging ourselves."

"Those who fell along the way--there were some who didn't stay with him--didn't have the faith in him," said Eva Marie Saint. "I don't mean to make him bigger than life but but he pulled us apart and put us back together again."

She spoke of exercises like "being a willow tree . . . you think it's easy but it's so hard. It sharpens the senses."

Mildred Dunnock remembers doing a scene at the Studio with the actor Will Hare. It was from "Auto-Da-Fe'" by Tennessee Williams, which takes place in the South and ends with a burning building. "We beat our brains out," she remembers. "When you finished a scene, the actors would stand still and the class would comment. I think this gave him time to think.

"Finally he said, 'Millie, I didn't see any heat.' I said, 'Dammit . . . I don't remember about the heat, we were trying to do a play.' He was trying to find a way to say what was missing. He would say things obliquely but if you examined them without passion they made sense."

"Those who learned at his heart adore him in a way that few other people I know are adored," said Arena Stage producing director Zelda Fichandler. "They adore him for causing their creative lives. He did release in each the private persona and allow that part of you to be functional."

But not everyone thought this marriage of psychiatry and theater was ideal. His daughter Susan, for example, wrote in her autobiography, "Bittersweet": "No impulse, from the most spiritual to the most destructive, was unacceptable as long as it could be transmuted into the creative experience. But I was confused by the fragmented lives I saw around me. So many actors functioned well on stage or screen but were cripples in their day-to-day lives."

Strasberg was not a founder of the Actors Studio, but replaced the original director, Robert Lewis, in 1951, three years after it opened. Elia Kazan, who was a founder, said later: "It's not our studio, it is his."

The Actors Studio was not a school, "It was a sort of gymnasium where actors came to work out between bouts," as Schneider put it. The "method" is a system of approaching a character that goes for the internal, believing the external will flower naturally if proper spade work is done. Strasberg's definition of acting was "creating real thought and experience under imaginary circumstances," according to his daughter.

Method actors are taught "relaxation" and "concentration;" to know their characters so well that they almost become them; thus when they are on stage they are not "acting," which has connotations of phoniness, but "being," which implies an emotional honesty that will affect the audience. They are taught to know what had happened to the character before as well as during the play, the character's relationships to other characters, even to the extent of imagining specific encounters. And the raw material for these imaginings, and for emotional moments in the text, is the actor's own life.

"The training paid off when I auditioned for "On the Waterfront," Saint recalled. "Gadge Elia Kazan asked me to audition with Marlon Brando . He gave me a set of circumstances to improvise but didn't tell Marlon. He gave Marlon a different set of circumstances without telling me. I was supposed to be a shy girl and he was supposed to get me to dance . . . Of course, the shyness and him trying to get me to break out of it was the core of their relationship in the film."

Fichandler notes that the technique is "a natural method. Its application is another matter. You have one kind of impulses for Shaw, and a different kind for Williams. You have to mold yourself to the author. I think maybe Lee did not make the leap to how an author has to influence the shape."

Roger Stevens, who worked with Strasberg in producing a series of plays in New York in 1961, said that Noel Coward attended a session at the Studio and was outraged. "He said 'You can't hear them. They're so busy thinking about themselves they aren't thinking about the play.' "

Strasberg has been criticized not just for neglecting performance values like voice production and movement, on which Stanislavsky placed increasing emphasis in his later years, but also for creating a cliquish, self-indulgent coterie that was dependent on his approval for their psychological health. Some say he preached a disdain for the crass commercialism of Hollywood because he was not sought after by major studios, and that his attraction for stars outweighed his concern for unknown artists.

Judging from his daughter's book, his relationships at home did not reflect the emotional honesty he expected of his students. She remembers, for example, coming home after a performance of "The Diary of Anne Frank" in whose title role she made her Broadway debut at the age of 17, and asking him for help on an acting problem. "Without a word he turned and walked into another room. I said to the friend who was with me, 'Why doesn't he talk to me? He talks to every stranger from the class who comes into the house, but he won't talk to me. I don't understand.' "

But despite the mumbling (which he is said to have decried), and his air of self-righteousness, Strasberg's contributions to the American theater are unquestioned by all but his severest critics. One of his most admired and courageous acts was returning to performing in the final phase of his life, earning an Academy Award nomination for his portrayal of a Jewish underworld kingpin in "The Godfather: II," and demonstrating in other pictures like "Going in Style" and the television movie "The Last Tenant" that whatever system he used, it worked. "They say that those who can't do, teach," said Wallach. "But he showed that isn't true."

He was energetic and enthusiastic until his last moments, dancing in a chorus line of Rockettes at the "Night of 100 Stars" benefit last Sunday night and working on plans to establish a company in New York that would use the talents of the established actors he'd worked with. Strasberg left another legacy of his work. Thirteen years ago he founded, with his wife Anna, the Lee Strasberg Theater Insitute, a school that has fewer restrictions for admission. According to a spokesman every one of his classes there was recorded on videotape. The tapes are available to all students.

During the summer of 1931 when the Group Theatre was forming, company members would write entries in a public diary, which was excerpted in Brenman-Gibson's book. One day Strasberg wrote:

John Dewey remarks that despite all our industrial and scientific achievement our civilization persists in what he calls a "magical" attitude. We have a feeling that somehow things will happen--we gamble--we hope--we dream--but we won't Work! We have lost our self respect, our faith in our own activity--we use Work only as a means--as a necessity--rarely as a means to an End. The actor wants everything to happen--he is so terribly hurt when it doesn't--his vanity--his self-confidence suffer--he unconsciously accepts the "magical" formula--he has a feeling that by being worried about it--by some kind of something that will happen he will create. He forgets he is a doer--an actor--creator and craftsman in one. I wish I could drive this into our actors in some way. Picture, 1, Lee Strasberg 1901-1982. By Ken Fell--The Washington Post; Picture 2, Lee Strasberg at the Actors Studio in 1968.