Pity the class of '81. This year's college seniors enter a supremely self-centered society at a moment of acute competition for the sweets of success.

But envy the class of '81, too. For to it is given the rare chance to develop a new sense of national community, a higher patriotism.

The "pig in the python" -- the great bulge in the population caused by the baby boom that ran from 1946 to 1965 -- provides the basic setting. As children, the products of baby boom drove their parents from the crowded cities to the suburbs, and the wide-open spaces of the South and West. As adults, they fostered an expansion of new consumer services. Like fast-food places, and discount houses, and cable television that all shared a stress on the small group or individual -- satisfaction in private.

As to public matters, the baby booms reached adult life just after Lyndon Johnson set in place the Great Society. Program to aid persons disadvantaged by reason of race or poverty did little for the vast majority of young people in quest of achievement. As the cost of social programs mounted, and their ineffectiveness became visible, the baby boomers became the shock troops for the attack on government and bureaucracy that has dominated national politics since 1976. The Reagan administration now rules the country in the name of those attitudes. At combines reductions in social services with a tax cut arranged on the principle that "them that has, gets." Add opposition to the draft and the affluent style, and there emerges a distinct sense of selfishness, even greed.

The authentic voice of the times is Jerry Falwell asserting that "material wealth is God's way of blessing people who put Him first." Or the young man depicted in an advertisement for pricey tennis shirts that says: "He knows what he wants. He wants it all."

Good students at the best universities are apt to get much of it. Here in Cambridge, shop talk centers around the hefty salaries being offered to graduates of the Harvard Business School. Engineers at MIT and new lawyers and doctors are also finding rich pickings.

Not so, though, for the more average students at less prestigious schools. Competition among the graduates is brisk. This year's cohort of seniors -- about 1.5 million -- is one of the largest on record. Not only do they have to scramble against one another, but they are also pitted against large classes of earlier graduates who have already cornered the comfortable spots in the work force.

Even as the competition intensifies, moreover, opportunity shrinks. Because of the continuous shift to services, attractive posts in industry dwindle. By choice of the electorate, public service jobs wind down. Openings in education, because of the population dip following the baby boom, diminish sharply. So what shapes up in the immediate future is sharp rivalry for fewer places in the sun. Selfishness, as usual, is bearing its bitter fruit.

An echo effect, fortunately, follows the population dip. By the end of this decade, the grandchildren of the baby boom will be appearing in large numbers. Even assuming a lower birth rate, there will be a rise in households. With it will come a need for more public services -- for safer streets, better schools, more effective transit.

At that point the hour of genuine opportunity comes round again. If they make the right choices, this year's graduates can realize the unfulfilled ambition of the '60s -- renewed cities, harmony among racial groups and a more equitable, less greedy society. But will they make the right choices?

David Riesman, looking back 50 years to his graduation from Harvard College, observed for the Crimson: "I am impressed by the large number of my classmates who have served education as trustees and philanthropists, and likewise have been acutely knowledgeable patrons of the arts . . . I wonder whether the class of '81 will produce a comparable sense of institutional loyalty and obligation, and of civic responsibility."