A rich crop of 10th anniversary observations sets this year apart from most others. For 1968 was a seedbed of history - a time when minorities staked claims in a way that fixed the pattern of events for the decade to come.

Looking back we can not only congratulate ourselves on the relative quietening of national life, we can also comprehend how there came into being the most discomforting feature of the present time: majority greed.

The first of the big events of 1968 was the self-assertion of the young. Student revolt reached the fringes of the Ivy League at Columbia, and a children's crusade, organized around Eugene McCarthy, upset a sitting president because of his prosecution of the war in Vietnam.

The tragic assassinations later in the year of two cherished leaders - Martin Luther King Jr. and Sen. Robert Kenedy - gave added scope to the demands of the racial minorities. Then there was the Chicago convention, and the joining of youth, the racial minorities and a new feminism in a movement that split the Democratic Party.

During the next few years all the minority movements made an enduring mark on American life, then peaked and lost momentum. The young people forced a change in the governance and curriculum in the major universities. As the core of the demonstration against the Cambodian incursion of 1970, they in effect obliged President Nixon to go for a negotiated end to the Vietnam War.

But once the war was over, "the movement" dissipated itself in enviromentalism and a variety of other causes. Students lost interest in politics, and after the recessions of 1970 and 1974 began once again to concentrate on good grades and entry to the lucrative posts in business and the professions.

The minority groups translated legislation passed under Lyndon Johnson into pratical gains across the board. They became a political force in the major cities and the southern states. They acquired more clout in the job market, and a leg up in entry to most universities. But the death of King removed the leader most able to unify the blacks. They overreached themselves in demands for school busing and various quotas. By the mid-1970s, Congress, the courts and the electorate were turning against civil rights.

The women made spectacular gains in the job market. Employment rose steadily, and they increasingly creamed off good positions in the professions and business.

But efforts to legalize feminist views of rape and abortion met resistance in the courts and legislatures. After first advancing at a great clip, the Equal Rights Amendment fell into a decline that now seems certain to end in failure to change the Constitution.

As the demands for special minority rights waned, the reaction of the majority waxed apace. There was set in motion a populist wave featuring resentment of the minorities, and the institutions and leaders that had favored them. A fine current example is the so-called tax revolt. It is the negative response of the majority to the levies on property used to pay for the service especially important to the minorities.

The move for public subsidy of students attending private schools and colleges is more of the same. It is a middle-class device for using the government to get back more of what was previously reserved for the poor.

Finally, there is the immense non-response to the energy crisis. It is case of the majority thumbling its nose at the authorities - both public and private - that have been burdening them for years with unpopular problems.

Comparing the then and now, accordingly, engenders mixed emotions. The tactics devised to foster minority aspirations are now being used by the majority to protect its taste for easy living. The violence has gone out of national politics, but so has the idealism. We are left with the sour realization that when minorities go on a spree, they inevitably license the appetites of the majority.