THAT SOFT scraping one hears is the sound of 300 students sliding their "Highlighters"-pink, green, yellow-over the significant passages in Edward C. Banfield's "The Unheavenly City."

Made available in the Coop last week in an unbound ($6.95) version especially rushed to Harvard to facilitate Government 146, the entire supply was snatched up in hours.

With good reason. The book will be the basis for that course's one hour exam on Friday (ominously the 13th). Students can only hope that Banfield tells the truth in his preface when he assures the reader, "I am as well-meaning-probably even as soft-hearted-as he."

What about "the unheavenly city?" Most significantly, it is not so unheavenly, after all.

Many of the problems that are supposed to constitute "the urban crisis" could not lead to disaster. They have to do with comfort and convenience, but they do not affect the essential welfare of individuals nor the good health of the society. Most of these problems could be solved rather easily if only the taxpayers were willing to pay the price.

The view from behind Banfield's rose-colored glasses shows the vast majority of city dwellers in pretty good shape, with things improving rapidly.

BANFIELD picks and chooses his "facts" well to support that contention.

Thus, he reports, "... one study predicts that substandard housing will have been eliminated by 1980." But that study is dated 1963, examined housing changes in the 1950s, and is obviously meaningless in the light of what happened to U.S. housing in the 60s.

To brighten the urban picture, he uses Bernard J. Frieden's data about the decline in the percentage of Negro families occupying substandard housing. But Banfield chooses not to mention Frieden's caution that, because of the increase in the black population, the number of nonwhite families in inadequate housing has increased.

Banfield rejects community action by quoting Marris and Rein ("Dilemmas of Social Reform"): "... the reforms had not evolved any reliable solutions." It is unfortunate that he did not go three sentences further to: "... at least in these five years community action developed a range of skills, concepts, organizations, models of action, which equipped the search with much more sophisticated means."

NAME ANY "problem" that still concerns some who lack Banfield's curious concepts; he has a surprising view.

Jobs? The supply of unskilled workers is decreasing. As this supply goes down, the demand will go up and "... the time will come when he will earn more than the skilled worker."

Riots? Banfield's chapter title alone should make his opinion apparent: "Rioting Mainly for Fun and Profit." Thus, "It is naive to think that efforts to end racial injustice and to eliminate poverty, slums and unemployment will have an appreciable effect upon the amount of rioting that will be done in the next decade or two."

And what about education? "Limited possibilities." The lower-class child has an outlook completely antithetical to education. So, reduce the school-leaving age to 14 (grade 9) and encourage (or perhaps require) boys who are unable or unwilling to go to college to take a full-time job or else enter military service or a civilian youth corps.

What about key studies that indicate putting low achievers in classes with high achievers improves the performance of the former? Banfield only mentions this, but without interest. Besides, he assures us, that would also worsen the performance of the high achievers when the proportion of low achievers "passes a certain point." We know of no data to support that view. And if it should be true, why pass "that certain point"?