THE OLD PURITANISM runs deep at Harvard. The University, we are reminded often, was first founded as a training school for young ministers. Here they would come to study liturgy and oratory, learning how to guide souls in righteousness and lead back the heretic and the remiss. Here, shivering in spare wood-paneled dorms and dining rooms, they would combat the freezing snow and wind outside with the fires of religious devotion they hoped to kindle.

Some of the men in whom Harvard lit the holy fire turned impure, fanatical, in the heat of the blaze. Then as now, Harvard's erudition and concentrated intensity alone could not insure that the leaders she nurtured and inspired would do good work in the world. Harvard men figured prominently in the conversion of enthusiasm to immoral horror that was the Salem witch trials, and students now-shivering in the same wood-paneled common rooms, watching the same inhuman blustery gusts of a Cambridge winter--may not have that much trouble imagining why The Crucible rings true.

These natural affinities are only part of what make this spare, direct production of The Crucible so effective. The South House dramatists seem to have everything on their side: the artistry of Miller's script, which mingles not-too-oblique political comment (the play was written during the McCarthy era) with personal and emotional drama; the New England blizzard outdoors, which highlights the "crucible" heat of passions boiling inside these outwardly contained, black-coated Puritan characters; the deeper cold emanating these days from Washington, making Miller's political preoccupations seem anything but remote; even the oak-panelled Cabot Living Room. They could hardly miss.

Director Reta Diekman wisely imposes little on these elements. Lynn Jeffries' sparse sets--just a bed in one scene, a table and candlestick in another, two benches in the third--typify the laissez-faire approach that lets the play, through a remarkably strong and consistent group of actors, do the talking. Interpretation and polish have been concentrated, where they belong, in the difficult timing of conversations in which characters constantly interrupt one another and in the placement of peaks of hysteria in a steady crescendo of tension that could have deteriorated into a two-and-a-half hour endurance contest of lung power.

Chris Keyser, in the crucial role of John Proctor, carries this approach vigorously to its full implications. Proctor, an upright but far from blameless Salem farmer, is tortured by the need to prove to himself and to his truly unstained wife Elizabeth that he is, in fact, a good man. As the witch trials become a raging mania in Salem, Proctor becomes inextricably involved, dragging all his past failings to light--including his liaison a year before with Abigail Williams, the girl accusing the Salem women of witchcraft--but can finally do nothing except die for his beliefs.

THE REST OF the cast, equally convincing, avoids the pitfall of letting all the characters sound alike as they frantically battle the same evil. Most of the roles fall in groups. But whether a terrified child, fanatical judge or desperate, martyred farmer, each actor manages to create an individual personality and consistently convey it. And the other actors on whom the show's believability rides--Maja Hellmold as Abigail, Jennifer Devine as Proctor's wife Elizabeth, and Jay Mattlin as Danforth, condemning to death by hanging all those who do not confess they are guilty of witchcraft--flesh out each role to the fullest. The small room echoes, and candlesticks shake as Mattlin, in a phenomenal portrayal of conscientiousness and religious fervor turned fanatical, forces everyone in the courtroom to bend to his will by pure dominance of personality.

Take on any level, The Crucible is a play to frighten an audience senseless. Proctor may triumph morally or he may not, as the viewer must decide. But Miller holds out no hope for the other victims of Salem's madness, nor any reassuring suggestion that that madness is confined to rage amid Salem's cold, rocky farms and Puritan gowns and breeches. In the sure hands of Diekman and company, the play doesn't need Cambridge's snowstorm, or Harvard's heritage, or even Cabot's dark wood fireplace to strike close to home.