Just when history was threatening to become the last refuge of the playwright without an idea, William Gibson has written a riveting play about an American historical event.

Perhaps a few of the characters and themes of "Goodly Creatures" which opened Thursday night at the Round House Theatre in Silver Spring, still need filling out and sharpening up.But even as a work-in progress, somewhat erratically performed, this is a play to start the mind churning, by a man with a firm command of his craft and a fascinating theme -- the forces that make purposeful human enterprise fragment and surrender their purpose.

"Grace" and "works" are the thematic cornerstones of the play, as they were in an ongoing theological debate in 17th-century Protestantism.

Grace -- the notion that man can receive God's spirit directly and intuitively -- is the banner that the charismatc Anne Hutchinson, a miniter's daughter, carries into battle with the Puritan clergy in the fledgling Massachusetts Bay Colony of the 1630s.

The ministers, themselves refugees from the authoritarianism of Anglican England, insist on salvation through works -- a set of rules administered by the church and derived from the Old Testament books of Moses.

Joining forces with other dissidents of varying motivations -- including merchants who object to a biblically derived profit ceiling of fourpence in the shilling -- Hutchinson becomes a threat to the church elders, who charge her with advancing "erroneous opinions" and hint that she may be a witch.

"After her lessons of grace, all can sin as they please!" one minister declares. "Woman," he warns her, "this is the grace of the serpent!"

Governor John Winthrop, the narrator and, to a degree, the tragic hero of the play -- the true hero is the colony itself -- takes a milder initial view of Hutchinson's heresy. "Is not the heart deceitful above all things?" he asks her. Winthrop, struggling to keep the colony together, wants to have grace and works all at once. But his is a lonely mission, and he winds up reluctantly agreeing with the ministers that Hutchinson and her faction must be purged. The colony's survival -- threatened by Indians on one fron and close royal scrutiny on the other -- demands unity at all costs.

The question of works versus grace may sound a triffle antique or esoteric, but surely similar forces are at work in a world that presents such alternatives as Freud and est, John Connally and Jerry Brown, and "inner" and "outer" tennis.

From "Goodly Creatures'" main theme, others spin away like sparks from a campfire. The role of economic growth as the eternal enemy of common purpose. . . . The tendency of any Utopian community to relax its rules to preserve security and consensus. . . . The subversive alliance of visionaries and opportunists that forms when any community aproaches middle age. . . .

Anne Hutchinson was eventually tried for "traducing the ministers" and banished to Rhode Island, where she and her children were massacred by Indians in 1643 -- a divine judgment, many of her old enemies back in Massachusetts concluded.

Gibson has made Anne -- deliberately, it appears -- an utterly earnest, undoubting advocate, nothing more nor less in private than she represents herself to be in public.

This is a reasonable choice, since the play is partly about the sacrifice of individuality that goes with fervent adherence to a cause. But it is a choice that ultimately limits the fine performance of Beth McDonald in the part. It wouldn't hurt to know if Hutchinson has any doubts about herself or the more shallow and mercenary members of her retinue. Even a heretic deserves more of a personality.

For related reasons there are moments, especially in the second act, when the issues tend to overwhelm the characters and story. But these raw elements reassert themselves resoundingly at the end of act two and through all of act three. Anyone who goes to "Goodly Creatures" supposing that a religious play cannot have action or suspense will be stunned, positively, by what Gibson and director John Edwards have accomplished.

As Governor Winthrop, Paul Haggard has the richest part in the play and invests it with nobility and complexity. Although bits and pieces of his narration are redundant (not to mention overwritten: "This does end our first part, short and sweet; the sour lies ahead"), the scenes between him and McDonald are strongly written and strongly played. Michael Littman makes a powerful impression too, as the stammering Reverend Wilson. There is an unmistakable fall-off in the quality of acting when we advance a few names further down the cast roll, but the parts are small, with almost everyone doing double and triple duty. And when the supporting players are called on to form a church choir or a forest chorus of Indians, birds or animals, they rise to the occasion.

"Goodly Creatures" is a play that ought to have a long life ahead of it. Go now, and you can say you saw it when.

GOODLY CREATURES, by William Gibson. Directed by John Edwards; scenery by Douglas A. Cumming; costumes by Leslie-Marie Cocuzzo; lighting by Daniel M. Wagner; music composed, selected and arranged by Christopher W. Patton.

At the Round House Theatre through Feb. 17.