HOW DO YOU explain the monumental impact of "Roots"?

We would begin with the quality and the character of the work.Quite apart from the television adaptation, the book is a tour de force. In tracing his family back seven generations to his African ancestor, Kunta Kinte, Alex Haley has performed an act of genealogical research that had been presumed to be impossible. But there is more, obviously, to the rage for "Roots" than the magnitude of Mr. Haley's personal accomplishment. The explanation, we suspect, has much to do with a coincidence of timing and technology. As to the technology, it is enough to note the awesome power of television. A black historian recently commented about his own long years of study of African and Afro-American subjects. "I have been working with the documents on which much of 'Roots' was based for my life," said Prof. Michael Winston of the Moorland-Spingran Research Center at Howard University. "Yet, I was amazed at the vividness with which that same material came across on that screen. I just couldn't believe its impact." Hen that power of television is wedded to the drumbeat and bugle blare of Madison Avenue, the result can be an immense audience.

But the miracle of modern communications is still only a part of it. There is also the question of timing. One can only guess what the impact of "Roots" would have been a little more than a decade ago when black Americans were marching and singing hymns in the streets in a historic demand for equality before the law, in the marketplace and in the eyes of their countrymen. But our guess is that impact then would have been to inflame without necessarily enlightening, to reinforce the sense of guilt of many whites and the sense of shame of many blacks. And our guess is that the impact would also have been nowhere near as pervasive and power. Would a major network have made the gamble to put "Roots" on the air, in eight installments at prime time, in the 1960s?

Even as the civil rights laws were being passed, it was obvious to many blacks and whites that legal equality in the strictest sense of the word would not make black Americans feel fully a part of the American society. And much of that complaint concerned the perception of blacks that the manner in which they had become Americans - in chains - was not yet fully understood by those who had become Americans by choice. It may not yet be fully understood. But it is not too much to say that the passage of the laws, and the the struggle that preceded their passage, helped clear the way for a deeper understanding - and "Roots." William Greider observed in this newspaper the other day that when the nation watched "Roots," it crossed "over deep water, stunning passage in the mass culture of America." Perhaps so. But we would venture the thought that white and black Americans alike were only able to make such a crossing because what had so recently been achieved made it possible for most white and black Americans to sit down as a people and hear the story of slavery with something more than guilt, on the one hand, or shame and anger, on the other. Our reading of the current national response to "Roots" would include at last some sense of shared progress and accomplishment, some collective measure of release and even pride in the way that whites and blacks are finally dealing with, as Mr. Greider put it, "our greatest national disgrace."

In the close of his book, Alex Haley express the hope "that this story of our people can help to alleviate the legacies of the fact that preponderantly the histories have been written by the winners." That is doubtless one of the contributions of "Roots". But the greatest contribution of the "Roots" phenomenon probably lies less in what effect it will have on future perceptions and behavior - in what it tells us about where we are going - than in what it comfirms about where we are, and how far we have come.