Robert Bolt's superb dramatic study of Sir Thomas More. "A Man for All Seasons," retains the rich texture which made it an international prize winner 15 years ago. With William Shust as guest artist, the Hartke Theater's production, directed by William Graham, is quality staging of a quality play. The run will be through March 20.

Shust's masterful performance not only is a reminder of what a fine actor he is, but also furthers the Hartke's design of guest professionals as stimuli to student actors. One solid player pulls others up several motches.

Chiefly known here for his electric performance in Marceau's "The Egg" at Arena Stage (the play later failed in New York with Dick Shawn as star), Shust is one of those highly respected professionals who hasn't cracked into wider fame.

Created by Paul Scofield, Balt's More is a penetrating study of a perceptive mind. Henry VIII's severance of "the connection with Rome" has inspired as much drama and film as any single event in history, and on this event Bolt spins a case of legal refinements. Because he so carefully has said nothing. More's legal position on Henry's marriage to Anne Bolyn is impregnable. "Silence," More says, "Is not denial." Only Cromwell's use of an upwardly mobile office-seeker creates the perjury which dooms hom.

Shust scores the points with commanding argument, making the most of Bolt's opportunities for humor. "I trust I make myself clear," Shust says, putting into his reading regret, mockery and compassion. It is a superbly detailed performance enhanced not a little by Shust's fine voice and resourceful readings.

Bolt's other contribution to the More story is The Common Man, whom he uses as audience guide and player of servant roles. Here, too, the humor is dry, penetrating and a celebration of The Common Man. James Kelly performs him with sly, open assurance.

Shust's contribution as partner is especially evident in his scenes with Robert Lesko's cromwell, the Richard Rich of David DiGlanantonio and the Spanish ambassador of Anthony Risoli, Patricia Flynn as the wife, Carolyn Swift Jones as daughter, Meg, and Bruce Burkhardt as William, create the family group of which only Meg graps More's legal refinements.

(This theme, by the way, is furthered in Paula Vogel's "Meg," the prize-winning play of the American College Theater Festival, to be played twice on April 5 at the Einsenhower.)

Graham's direction appreciates the drama's inner rhythms, a too-often ignored aspect of staging. It is a handsome production, with set and costumes by Philip A. Graneto and effective lighting by James D. Waring. Phone reservation at 529-3333.