BOOK REVIEW / NONFICTION : When Poverty Takes Hold of Brave Souls : AMAZING GRACE: The Lives of Children and the Conscience of a Nation <i> by Jonathan Kozol</i> , Crown Publishers $23, 286 pages

It’s a mystery to many people, particularly those who have pulled themselves up by the bootstraps, why the chronically poor in this country fail to better themselves. The United States is the land of opportunity: Why don’t those on the lowest rungs of the social ladder work harder, resist temptation, save their nickels, plan for the long term? If I can make it, say those who have, so can Joe Blow, regardless of race or background, education or environment.

It’s doubtful any single writer could change such sentiments, which have become increasingly popular in recent years, but if anyone can, it’s Jonathan Kozol. He has spent decades recording the plight of the poor, especially poor youth, in the United States--notably in “Death at an Early Age,” “Rachel and Her Children” and “Savage Inequalities”--but here he has produced perhaps his most affecting book. “Amazing Grace” is small in scope, recounting friendships made and conversations experienced over the course of two years of visiting New York City’s poorest neighborhood, yet this volume has the tone and power of elegy.

Violent, premature death is commonplace in the Mott Haven section of the South Bronx and Kozol gives many of these everyday extinctions their due. “Amazing Grace” isn’t a necrology, however--or rather, it’s a necrology of a different kind, for at bottom, Kozol is bearing witness to the death of a dream, of sustaining hope, of caring itself. In his conclusion, Kozol writes, “I have never lived through a time as cold as this in the United States.”

Kozol will convince all but the most skeptical reader that the South Bronxes of this country have become islands unto themselves, quarantined from influential people and places to such a degree that they are moribund, slowly dying of physical and spiritual malnutrition. As one 15-year-old Harlem resident tells Kozol, living in her neighborhood is like being an object put in a garage so the owners “don’t need to think of it again.”

Kozol sees the South Bronx largely through the eyes of a woman he calls Alice Washington, a 50-year-old African American who hasn’t been able to work since contracting AIDS (from her long-departed husband) and then cancer. Washington isn’t self-pitying or resentful, or even angry, most of the time: She’s simply “all worn out from mournin’,” resigned to being disregarded by those with money and authority.

The power of Washington’s story lies in the horribly routine nature of her existence: asking the drug dealers loading guns on the fire escape to go elsewhere, being told by policemen that they delayed responding to a robbery report in her building because they were “scared,” being treated with casual contempt by shopkeepers and bureaucrats when forced to travel outside the South Bronx.

When Kozol mentions the idea of “compassion fatigue” among the well-heeled, Washington replies, “I don’t understand what they have done to get so tired.”

If Washington gives “Amazing Grace” its moral center, the children Kozol encounters make it heart-rending. Washington’s granddaughter, whose nightly prayer is “God bless Mommy. God bless Nanny. God, don’t punish me because I’m black”; Anthony, the 12-year-old who gives Kozol tours of his neighborhood, worships Edgar Allan Poe and dreams of being a novelist. Of Anthony and others like him, a South Bronx poet tells Kozol, “If they cannot sing, they scream. They are vessels of the spirit but the spirit sometimes is entombed; it can’t get out, and so they smash it!”

Kozol has written “Amazing Grace” as a testament, but as this last quotation indicates, it’s a warning against complacency too.