If Sir John Gielgud wins the Best Supporting Actor Academy Award this year, as many critics expect, he will be able to say in all truth that the butler did it. As Hobson, Dudley Moore's acidulous (and achingly funny) manservant in Arthur, he steals scenes repeatedly. And his co-stars love him for it. "He's a totally sweet and unpretentious man," says Moore. Adds Liza Minnelli, "You want to hug him until you cry."

On top of those encomiums, even if Arthur doesn't beget Oscar, Gielgud, at 77, is having a vintage year. His patrician face is turning up with almost bewildering frequency: In addition to Arthur, he is currently appearing in Chariots of Fire, as a Cambridge don, and in the new movie about D.H. Lawrence, Priest of Love, as a British censor. In the past two years he has been in no fewer than nine films. He has also published his fourth book, a memoir, Gielgud: An Actor and His Time (Crown, $14.95), and between movies has appeared in TV versions of three literary works, Evelyn Waugh's Brideshead Revisited (upcoming on PBS), a Roald Dahl short story and a serial spun from an Agatha Christie mystery.

Why, at an age when most men are ready for pipe and slippers, is he maintaining such a pace? "I have nothing else to do," he deadpans. "I'd be miserable if I weren't doing these films. My family are nearly all gone, and I'm not mad about the few that are left. I haven't enough else besides acting to occupy my time." The movies are a welcome change. Twenty years ago, Sir John thought, prematurely, the curtain was coming down on his stage career. With the emergence of playwrights who were invariably "young" or "angry," he envisioned no place for an old Shakespearean like himself. "When I saw [John Osborne's] Look Back in Anger," he recalls, "I thought my number was up. One is afraid of being old-fashioned and hammy."

Gielgud came into acting almost by birthright. His mother's family had been in the English theater for generations; Ellen Terry, the acclaimed Shakespearean actress, was his great aunt. The Gielguds, expatriate Polish nobility, also had a theatrical connection: Aniela Aszpergerowa, John's great-grandmother, was a leading interpreter of Shakespeare on the Lodz stage. At 17, despite the misgivings of his stockbroker father, John accepted a scholarship to the Royal Academy of Dramatic Art. "I made a deal with him that if I were not successful by 25, I would become an architect." At 19 he was onstage as Romeo, and at 25, as Hamlet, he was the toast of London. "The actors in the Edwardian period never played Hamlet until they were 40—John Barrymore was 45 when I saw him," Gielgud says. "The tantrums and despair of the opening scenes were perhaps more poignant because I was so young."

Gielgud played Hamlet until he was 41, and his interpretation is generally conceded to edge Sir Laurence Olivier's as the greatest of our age. With his friend Sir Ralph Richardson and Olivier, Gielgud is one of the reigning British actors of the century. Sir John continued to enact the big roles in the Shakespearean repertoire until 1974, when he appeared in The Tempest for the last time. "I don't want to go back to Shakespeare," he says with a twinkle in his eye. "It's very nice to have left that behind. I don't want to disillusion people by not being very good anymore." Over the years Gielgud has successfully tried his hand at directing (even opera), producing and writing.

Offstage, Sir John's life has gone in a new direction, like his career. Four years ago he left the London town house that had been his home for 30 years ("I've adored London all my life, but it's so ruined now—quite as dirty as New York, if not dirtier"), and moved into an 18th-century carriage house in the village of Wotton Underwood, near Oxford. It is a perfect setting for a man from the stage, lacking only a proscenium arch. The principal room is a Georgian double cube, 60 feet long and 30 feet high, with a Chinese red floor, gilt and silver moldings and an enormous chandelier. An adjacent aviary is filled with screeching parrots. He shares the digs with two Shih Tzus and his companion. "I live with this chap," Sir John says. "He's a tremendous friend of mine. He cooks and does all the redecorating of the house. He also is marvelous with the garden.

"I don't see many people," Gielgud says. "I don't go to parties anymore. It's wonderful now, in my 70s, to say, 'I'll do this, and I won't do that.' Recently I started to make a list of things I couldn't do," he quips. "It would fill a dictionary. I can't swim, play cards, drive a car or skate. It became quite alarming. After 77 years on this earth, I really can't do anything except enjoy the theater, go to the movies, observe life and act a little."