NOW NO LONGER TABOO to the stage, certain sensitive issues consistently generate powerful and thought-provoking drama. Examples of homosexuality or suicide come to mind--problems we can empathize with although they don't necessarily touch our lives directly. The case of bigotry, however, stirs emotions by touching a deeper nerve that is all too familiar to many people. In MASTER HAROLD..and the boys Athol Fugard forces us to probe not only the problem, but also our own psyches.

Fugard, a white South African, sets the play in his native country in 1950, a time when the specter of apartheid was practically ignored by, if not unknown to, much of the rest of the world. The pain and anger expressed sounds a chillingly realistic note, as we share the author's largely autobiographical introspection.

The drama opens with Sam and Willie, two middle-aged Black servants, cleaning up the teahouse owned by Harold's family. They are soon joined by teen-aged Master Harold, returning from school. Having spent time with these men since he was a child. "Hally" banters with them as friends, discussing the details of his morning. Styling himself as a typical liberal egalitarian student, he laments that "It's a bloody awful world when you think of it, what people do to each other...Where's progress? Every age has got its social reformer." Sam, the more intelligent and articulate of the Negro servants, easily replies, "Where's ours?" which Hally shrugs and offers. "Who knows, maybe he isn't born yet." Hal later chastises. "You've never been a slave, Sam. Besides, South Africa freed your ancestors long before the Americans did."

IT IS CLEAR from the play's onset that Hal regards Sam as a 40-year-old younger brother whom he can impress and teach and argue with. Willie joins the conviviality, but when the playfulness strikes a sensitive chord. Hal quickly reproaches him. Whereas Willie accepts the reprimand as a cowering child. Sam regards it half-seriously, as a request rather than a demand. He refuses to be treated like anything but an equal, and here the conflict begins to develop.

Sam edges closer to danger when he begins to probe Hal's insecurities as an older, but equal friend might. But he penetrates the boy's shallow self-esteem too easily, and the frightened Hat runs for shelter behind the person of the superior white master. Sam refuses to accept the yoke of servility. As the tension peaks, Hal spits in Sam's face. The expressions of each of the characters fires the climax without a single line being uttered: pained horror on Willie's face, bittersweet remorse for Hal, and disappointment and remarkable self-control in Sam. "A long time ago, I vowed to try to do something," Sam broods, "but you showed me that I failed."

In the one sentence. Sam epitomizes Fugard's profound irony: Master Harold, insecure and ashamed of his situation, is pitied by his Black servant, who in turn, despite his position, retains pride and human dignity.

Zakes Mokae brings a sense of quiet majesty to the part of Sam--a role which he originated on Broadway, earning a Today Award for his powerful performance. Mokae presents a poised and insightful, but self-restrained Sam, fully aware that he, not Hal, has the more valuable lessons to impart. While there is a disturbing lack of tension when Sam first debies Hal's demand for proper respect, the climatic strength builds up quickly to Mokse's resigned yet underfeated pronunciation "Yes, sir, Master Harold!"