Jerry Bauer/Happer Collins

Edward P. Jones, author of "The Known World."

Friedrich Engels once said that he learned more about postrevolutionary French society from Balzac than from ''all the professed historians, economists and statisticians of the period together.'' The same might be said of slavery in America and these two first novelists, who write about its history not as if it were fixed in time, safely over and done with, but as if anything could happen in the chaos of the moment.

Edward P. Jones's novel, ''The Known World,'' opens with the death of a master of 33 slaves in antebellum Virginia. None of his property grows teary-eyed, though, at the news that Henry Townsend has died. They surely don't know that when he obtained his first slave he wanted to be ''the kind of shepherd master God had intended,'' someone who would provide ''good food for his slaves, no whippings, short and happy days in the fields.'' By his death, he had learned his lesson. It seems he had no choice but to chain a runaway slave in his barn and pay a Cherokee patroller to slice a third of his ear off. A familiar story, perhaps, so far. There's a difference, though. Henry Townsend is black.

In 1855 in Manchester County, Va. (a fictional place standing in for an actual historical landscape), we learn that ''there were 34 free black families . . . and eight of those free families owned slaves.'' Henry Townsend's freedom had been purchased by his father, Augustus, a carpenter who bought his own freedom with money earned from his carvings and furniture, then over time bought his wife and son out of slavery. Henry himself financed his first slaves by making boots and shoes. But why would a former slave himself buy slaves, especially against the wishes of his father? Though the novel never explicitly addresses this question, readers get the message: because slavery was legal and believed to be sanctioned by God, because wealth and status consisted in owning human flesh -- and because Henry ''wanted to be a better master than any white man he had ever known.''

Among the many triumphs of ''The Known World,'' not the least is Jones's transformation of a little-known footnote in history into a story that goes right to the heart of slavery. There are few certified villains in this novel, white or black, because slavery poisons moral judgments at the root. As Jones shows, slavery corrupts good intentions and underwrites bad ones, yet allows decency the odd occasion -- but only by creating such an enormous need for it.

The freshness of his story lies in its very incongruity and strangeness. Henry's first slave, Moses, takes more than two weeks to process the news ''that someone wasn't fiddling with him and that indeed a black man, two shades darker than himself, owned him and any shadow he made. . . . Moses had thought that it was already a strange world that made him a slave to a white man, but God had indeed set it twirling and twisting every which way when he put black people to owning their own kind. Was God even up there attending to business anymore?''

Good question. A known world is one seen and understood by God and therefore fixed and ordained. Jones's world, by contrast, is one that could come to pieces at any moment. After Henry's death, his wife grows dreamy and passive while her slaves betray one another or run off. Jones writes with a sense of narrative foreboding undercut by the erratic nature of events, and the result is a portrait of a society that is seemingly immutable but as tentative and fragile as the map of the Americas for which the novel is titled, hung on the local sheriff's wall. This map finds its echoes in the book's final chapter, when, by 1861, the known worlds of Manchester County and of Henry's plantation have themselves become huge wall hangings in a hotel in Washington, the folk-art creations of one of the story's runaway slaves.

Jones's talent for conjoining the ordinary and the marvelous is partly that of a miniaturist with a novel to write. A finalist for the National Book Award for his collection of stories, ''Lost in the City,'' he constructs ''The Known World'' as a clockwork mechanism of stories within stories, some appearing as single phrases in a sentence, others spanning the whole book. From Henry's death, he spirals back to the history of a multitude of characters whose stories begin as faraway trickles before they swell into rivers. These characters survive by negotiating mazes of moral contradiction, but they speak with a raw and lyrical bluntness.

Jones has an exceptional ear for speech now buried in the past, though its echoes remain. His own narrative style is doggedly declarative, slow, persistent, imperturbable and patient, but it gets the job done. To call this novel mule-paced is not to be captious. Mules are noble animals in the world of the novel, and smarter than horses -- they won't work until they drop. I could have done without the gratuitously bloody ending, if only because by then Jones has so effectively shown that the death of the heart was slavery's worst horror. Still, ''The Known World'' is an achievement of epic scope and architectural construction, which nonetheless reads like a string of folk tales told by someone slyly watching for your reaction -- tales told by a conjurer who distracts you so well that you never know what hit you.

Another novel about slavery, this one set in New York State (where slavery was legal until 1827), tells the story of the remarkable Sojourner Truth. The despised and the revered are first to lose their humanity in historical depictions, and even during her lifetime Sojourner Truth was both. Jacqueline Sheehan's ''Truth'' attempts to flesh out this abolitionist heroine and bring her down to earth, and often it succeeds. Sheehan depicts the basic facts of the life of this slave first known as Isabella: her childhood in a cold, dark cellar; her sale at auction at the age of 9; the brutal whippings and sexual torture she experienced at the hands of two of her owners; her attachment to a religious charlatan named Matthias; her visions of God, who instructs her to take the name Sojourner Truth; her meetings with Frederick Douglass and Abraham Lincoln; and her electrifying speeches against slavery and for women's rights.

The most gripping scenes may very well be those that explore her involvement with a religious community called Mount Zion and its founder, Matthias. This section of the novel describes a conjunction of religious and sexual frenzy involving communal baths, the search for a ''match spirit'' to sleep with, beatings, fits and ultimately a murder trial. It alone could have been rich material for a novel. And it also raises a fascinating question: how often has American religious history played variations on ''Tartuffe''?

Sojourner Truth herself comes most fully alive in Sheehan's final pages. There the excitement of her public appearances, her simple and profound eloquence, her caustic wit in handling hecklers, her ability to ''toss a blanket of laughter over the ice of truth,'' are all strikingly captured. But can we call this book a novel? Sheehan never solves the problem of how to shape her material, and the resulting story often reads less like a work of fiction than a biography in drag. (Unlike Jones, who includes no notes or appendixes, Sheehan adds a bibliography and a timeline.)

The bulk of the narrative describes Sojourner Truth's early life, told in the first person with a pell-mell forthrightness that seldom lets up but seldom transcends itself either. Most first-person novels have layered narrations in which a younger self on the edge of experience exists within an older self engaged in looking back -- an older self who renders the life, who gives it structure or design. In ''Truth,'' the chronological narration seems instead to attenuate the life, to make it little more than a recitation of one thing after another. Nor does Sheehan attempt to capture a 19th-century vernacular; we must take her contemporary language on faith as a sign of her central character's spirit, not a material embodiment of it. As a result, although Sheehan's writing is often lively and vivid and although her feel for historical detail is fine, her novel never really feels like an artifact of the past. John Vernon's most recent books are a memoir, ''A Book of Reasons,'' and a novel, ''The Last Canyon.''

Copyright 2003 The New York Times Company. Reprinted from The New York Times, Books, of August 21, 2003.