WE CLIMBED iced steel stairs up the face of Washington Cathedral, unlocked a makeshift door and stepped into a cozy closed-in scaffoldingwhere two stone-carvers were brushing dust off the great central sculpture over the west portal.

"How ya doin'?" asked Frederick Hart, the sculptor.

"We're done," they said.

Long pause.

"You're done?"

"Just now. Couple hours ago. It's finished."

All three men seemed slightly dazed. They shook hands. For two solid years stone-carvers, sometimes four of them, had been chipping away at the swirling shapes of "Ex Nihilo," 21 feet of Indiana limestone, 15 feet high, 28 inches deep, with its eight life-size nudes literally being formed from the primordial cloud. For four solid years Hart had lived with it, as a clay sketch model, then as a one-third-scale model, then a full-size model and finally the plaster cast from which it was carved.

And now, suddenly, it was finished.

Rick Hart is 38, and this is his first major piece. He has been carving for 10 years, ever since he won the competition while he was a stone-carver apprentice at the cathedral. He will stay with this job another two or three years, parttime, completing the other tympanum reliefs depicting Night and Day, plus the statues of Peter and Paul which will flank the portals. His Adam already has been dedicated and the Paul figure should be ready by spring.

A curious career. "I've been doing this longer than the siege of Troy -- I'm serious -- withdrawn, isolated from the art world. After 10 years I still have no complete works in public view."

He was about to quit his carving job in 1969 when he heard about the competition to portray the Creation, not with the usual bearded-old-man God but as the Life Force. He was set on fire. For three years he pondered, studied and sketched a plan that would balance abstract shapes and human figures, would tie the whole west facade together in a coherent statement. Influenced by Teilhard de Chardin's efforts to reconcile science and religion, he conjured a whirling universe of stone, with saints whose robes seem to billow in the hurricane of creation, with human beings whose faces, though taken from 25 different models, seem anonymous, universal, blank tablets to be written upon.

"It's one thing to get it all working together. Then you bring it up to full scale, which is an entirely different animal, a different presence. Then you have to make it sing."

With 10, not to say 13, years of a career riding on this work, Hart has plenty to say about it. He feels it will be a great call to arms for modern art, which he says desperately needs something magnificent, something grand, to lead it from the slough of "minimal" and "interesting" and "conceptual" to once again seek beauty and truth, to explore the infinities of human nature and the universe.

"This thing is an anachronism -- like the Renaissance," he said. "It goes for beauty on a high level, it has substance, it tries to sum up a culture. I want it to be understood. I have no patience with the deliberately obscure. The greatest works are never obscure. This isn't art for art's sake, it isn't about art but about life."

He loves the notion that "this great big goddam radical breakthrough" should be happening in a scholarly gothic re-creation in, of all places, Washington, D.C.

But now Hart is finished with his long marriage to stone. For six months he has been experimenting with Lucite, relatively unexplored by sculptors -- "a dark art," he says, unbelievably hard to cast or control. He wants to play with multiple exposures in 3-D. He wants to find a way to make shapes emerge from light itself.

It's about as far as you could get from chipping saints out of stone and still be a sculptor.