In 1938, Norma Shearer gave a party for Robert Morley, newly arrived in Hollywood to make his movie debut as Louis XVI to her Marie Antoinette. During the evening he asked, ''How did you become a movie star?'' and was immediately flustered at his tactlessness. But Norma gave him her perfected gracious smile and replied, ''I wanted to!'' Her career was a triumph of will. When she came to New York from Canada at 18 in 1920, Flo Ziegfeld advised her to forget it. She was short, with heavy thighs, bad legs, and a cast in one eye. Though she did exercises all her life to correct this last defect, she never entirely succeeded, and in any Shearer film there are moments when her eye is on the sparrow.
She began as a billboard model, ''Miss Lotta Miles'' for Springfield tires. Can anyone under 50 appreciate what a big star the former tire model became? Like the more talented Irene Dunne, she specialized in ladylike roles, re- creating stage parts played by Ina Claire, Lynn Fontanne, and Katharine Cornell. Without stage experience herself, she had studied these ladies from balcony seats during the 1921-22 Broadway season. When she undertook the role of Amanda in Private Lives, her studio sent a crew to film Gertrude Lawrence and Noel Coward in the 1931 Broadway production, for Norma to study. It's lost. How one would like to see it!
In the 1930s, married to Irving Thalberg, the boy-wonder producer who inspired Fitzgerald's The Last Tycoon, she was Queen of the Lot at MGM. ''What chance do I have now?'' Joan Crawford griped. ''Norma sleeps with the boss.'' Shearer's status was an ambiguous blessing. Besides having a heart ailment that killed him in 1936, Thalberg was fatally afflicted with gentility. He cast his wife in movies with literary pretensions O'Neill's Strange Interlude, The Barretts of Wimpole Street, and as a mature Juliet in a suffocatingly tasteful rendition of Shakespeare. Norma gets a bad rap for these turkeys, but the reverence in which Thalberg's contemporaries held him is an unexamined delusion.
Gavin Lambert is a British-born Hollywood insider whose The Slide Area (1959) is one of the sharpest works of fiction ever written about southern California. His book on Shearer, sympathetic but shrewd, is a definitive portrait of a woman remembered by one of her protégés, Robert Evans, as ''a very singular person underneath all the charm and graciousness, tough as a teamster.'' Lambert recounts five meetings with her in 1973-74, first at a Beverly Hills restaurant where she made a calculated, spectacular entrance at 71. We feel the impact of a sacred monster.
Since Shearer was a regal society personage, Lambert provides a fascinating social history of the vanished Hollywood party world she ruled alongside William Randolph Hearst and Marion Davies. Peculiar figures make cameo appearances. Edgar F. Magnin (''Rabbi to the Stars'') married the Thalbergs in 1927 and included a movie plug in his sermon at Irving's funeral nine years later: ''The love of Norma Shearer and Irving Thalberg was a love greater than that in the greatest motion picture I have ever seen Romeo and Juliet.''
The Thalberg marriage was ''an MGM-style merger based on close mutual interests,'' according to Lambert. There was also genuine affection and respect. Shearer was faithful to Thalberg, but after his death her suppressed sexuality emerged in a series of affairs with such men as Jimmy Stewart and George Raft. Lambert has one piece of major dish: Shearer's brief affair, at 36, with the 16-year-old Mickey Rooney, which almost sent Louis B. Mayer into apoplexy. At 40, her movie career over, she married a Sun Valley ski instructor 12 years her junior and lived happily ever after.
Shearer made one movie I unabashedly love, the maligned Marie Antoinette. Author Donald Ogden Stewart, asked to tackle the much-rewritten script, noted that the main problem was to find ''the best way of explaining the French Revolution in terms that would not lose audience sympathy for Norma Shearer.'' Never mind history, it's one of the magically romantic movies of its time. You have to sit through a half-hour of excruciating girlishness before Shearer takes hold at the moment she utters the unlucky line, ''I'm sorry you don't see it my way, Louie,'' and embarks on a course of dissolute pleasure. It's a big, extravagant performance. By the end, helped by Morley's touching portrayal of Louis XVI, she becomes powerfully affecting. No wonder it was her favorite role.