COMMON GROUND; A Turbulent Decade in the Lives Of Three American Families. By J. Anthony Lukas. Knopf. 659 pp. $19.95.

FOR A DECADE, from 1968 to 1978, journalist J. Anthony Lukas hovered over Boston as it went through the social upheaval experienced by many cities in that period but which in Boston's case was compounded by a bitter and violent struggle over court-ordered school desegregation.

Not lost on people all over this country was the ironic spectacle of Boston -- that bastion of 19th-century Abolitionist sentiment, the city that once claimed for itself all sorts of cultural and civic and moral virtues (and lectured others through so many spokesmen) -- had now, late in the 20th century, turned into a scene of everyday publicly enacted racist hate. Nor was everyone ready to take a hard and long lok at this continuing tragedy -- to see beyond the quick "liberal" judgments (aimed from comfortable suburban homes at inner-city white working-class people) or the equally reflexic "conservative" pronouncements which concentrated on the terrible wrongs, say, of "busing" -- as if hundreds of thousands of white children hadn't been bused, for years, to all- white schools without a murmur from anyone, anywhere.

For Lukas, the point was to move firmly beyond political rhetoric -- to learn from particular individuals: black and white; well-to-do and not so well off and quite poor; vulnerable and modestly comfortable and powerful. His "research methodology" was quite simple -- utterly unworthy of some of the fancy proposals sent the National Institute of Mental Health: go and find a few families, get to know them well, tell others their stories -- what happened to certain people in their minds and hearts as they became, in their own ways, historical actors, if not protagonists of sorts.

In Common Ground, Mr. Lukas offers clear, lean prose -- free of overwrought and self-serving generalizations. His posture is not that of the very smart one who has figured it all out and begs only the reader's willing, if not gullible, acquiescence. He has spent many years doing his work, that of being a close watcher of and listener to certain families -- and so doing, he has risked losing our interest, because racial conflict in any part of this country no longer commands our nation's concern to the degree that once was the case. Yet, the result of such a prolonged effort is a text illuminating and honest enough to assure (one hopes and prays) the widespread and sustained attention it most definitely warrants.

The book starts (and ends) with the Divers, well- educated, earnestly compassionate white Protestants. Colin Diver went to Harvard Law School, worked for Boston's Mayor Kevin White in his early, reformist years in office, chose to live in a downtown neighborhood, only somewhat gentrified, and located hard by some of the poorest, black sections of the city. Joan Diver for a long time has been active in progressive Boston philanthropy. Their two sons went to school in an urban public school, one of many Boston schools Judge Garrity had under his wing for so long. We also meet the McGoff family of Charlestown, Irish Catholic and humble and struggling all the time to break even. Families such as this one were suddenly in the midst of a major educational upheaval. Their neighborhood schools were the recipients of children from across the city; and not rarely, their own children were sent equally long distances to places writers and social critics (from afar) call "ghetto schools." The third family, of course, is a black one, poor and with much pain and suffering in its collective past, the Twymons.

It is Lukas' desire that we understand more than the recent squabbles and hurdles, the personal victories and defeats, which the members of these three families have enced. He digs long and hard into their American origins and, so doing, gives us a magnificent social history of Boston -- of America, really: the 19th- century origins of today's racial trouble. We are reminded, inevitably, that what seems so especially worrisome or dismaying in our time has more than its match in the past -- the terrible hate and violence which characterized the relationship, for example, between Boston's Yankees and its Irish immigrants over the generations. As a matter of fact, before the marked increase of blacks in Boston (a post-World War II phenomenon) the city was all too full of suspicion and fear and resentment and grudges and bad blood -- a chronic and nasty anti-Semitism, a virulent snobbishness on the part of Protestants towards Catholics, and within the Catholic Church, serious ethnic divisions which were, alas, excuses for destructive gang wars. The nostalgia one occasionally hears for the "good old days" of Boston's past -- as so often happens with nostalgia -- is born of a wish not to look carefully at that past.

But Lukas not only carefully looks way back, he scans the present far and wide; he shows in the case of each family, parent and child alike, how a particular political crisis (a federal judge's order that Boston's schools be racially balanced) fitted into their ongoing lives -- called forth their strengths, their ideals, or played into their weaknesses, their fears, their worries. As he does so, he demonstrates a brilliant and subtle narrative skill -- the ability to offer not just piecemeal accounts of black urban life up North, or of the fierce white resistance to court-ordered busing, or of the vicissitudes of upper middle-class idealism, but a thoroughly coherent overall view of how individuals get caught (and hurt or challenged to new levels of personal and ethical achievement) by the political and cultural changes that take place in their lives.

IN MANY RESPECTS this book belongs in the tradition of literary- documentary studies -- the kind of work James Agee did upon returning from his stint in rural Alabama in the 1930s, or Orwell did when he wrote of his experiences among England's coal miners in that same decade. They were both novelists attempting to understand social reality; they did so by meticulous resort to the ordinary details of this life as they saw it lived by certain others. Their writing was suggestive rather than categorical -- geared to an evocation of individual variation rather than the requirements of a universal statement. They had no ideological purpose in mind; if anything, they aimed to show the folly of such an angle of vision -- the arrogance of social or political theory that asserts itself at all costs, and to the devil with those whose lives end up paying for what has been argued tenaciously, declared unequivocally, demanded unreservedly. Without question J. Anthony Lukas now belongs in their company -- his book well up to their high and idiosyncratic standards.

There are, therefore, no series of "findings" or "conclusions" to be found in this strenuously exact rendering of a decade's impact on certain individuals. The author weaves their stories together skillfully, interrupting only to give us important and highly instructive cameo appearances: Mayor White; Cardinal Madeiros, and his incredibly imperious distant predecessor Cardinal O'Connell, as well as his more recent, and more kindly one, Cardinal Cushing; the Boston Globe's editor, Tom Winship; the one- time leader of the anti-busing forces, Louise Day Hicks; and of course, the federal judge, J. Arthur Garrity, who took so very much of a city's ongoing life into his hands for so very long.

What we get, finally, is an extended and well told tale -- the making of which depends upon what has actually taken place, however, rather than what someone constructs in his mind. When the author lets us know that the sun shone on a day that a housing project was dedicated, when he bothers to tell us about small quirks or compulsions in seemingly obscure men, women or children, when a snow storm gives him pause, or when the reading (or drinking) habits of a man or woman seem to matter much to him, when he stops to remind us of the distant Puritans or the recent reforms in the Vatican, when he does not shun irony and ambiguity and paradox and luck (good or bad) and chance and inconsistency and contradiction (in favor of all too neat formulations), we begin to realize, again and again, that a gifted, patient and wise storyteller has found his way into a situation that begs for such a presence. For a long time, surely, many thousands will be greatful recipients of that meeting between writer and a scene -- as they find out how a white liberal family fights for its own kind of integration (the Divers eventually move back to the suburbs), and most of all, how class as well as race bears down upon everyone, enabling righteousness, if not smug hauteur in some, eliciting frustration if not meanness in others, black and white alike.