The final act was rich in paradox. Richard M. Helms, a son of the American establishment and a keeper of its official secrets, stood in the courtroom of Barrington Parker, a black judge appointed by Richard M. Nixon, to receive sentencing.

For 35 years Helsm had lived in the world of the intelligence community, abiding by its [WORD ILLEGIBLE] values and obligations - the [WORD ILLEGIBLE] that carved the path to Judge Parker's courtroom.

"Richard Helms will bear the scar of a conviction for the [WORD ILLEGIBLE] of his days," said Edward [WORD ILLEGIBLE] Williams, his attorney [WORDS ILLEGIBLE] incurred in the service of his country for doing what by his lights and conscience was the right thing to do."

But the plea, however poignant, was rejected by Parker, speaking with the authority of the federal judiciary. "From this day forward, let there be no doubt: no one whatever his position in or out of government, is above the law or is relieved from complying with it," said the judge.

There the issue was joined and decided with the punishment [WORD ILLEGIBLE] by Parker: a two-year suspended jail sentence and $2,000 fine.

Symbolically, Helms before the bench represented the American intelligence community itself - battered as it has been by the revelations two years ago that it has violated the bounds of statutory charter and in some cases transcended accepted standards of international behavior.

There are those who will argue that the Justice Department's plea-bargaining terms for Helms were too lenient, that the government would have been less generous had the accused not been a respected member of the governing elite. Yet others, surely the prestigious constituency of Helms' Washington friends and patrons, will respond with bitterness to the sentencing - echoing the emotions voiced by Williams.

On one occasion in February, 1975, the lions of Washington social and political life gathered at dinner to pay homage to Helms, who had already perceived the trouble ahead. The group included Averell Harriman, Stuart Symington, Robert S. McNamara, Henry A. Kissinger and the Bradens, columnist Tom and hostess Joan, who issued the invitations. The wagons were being circled even then.

For President Carter and for his Attorney General, Griffin Bell, the Helms case has been a painful and vexing inheritance Bell has spoken openly of the pressure, the entreaties from the influential partisans of Helms. Alfrom the Ford administration, most since the administration took office the negotiations have been under way between counsel for Helms and Carter's Justice Department.

At the heart of the Helms case was the issue of giving untruthful testimony under oath to a duly-constituted committee of Congress, the Senate Foreign Relations Committee.

Under questioning by his longstanding friend and patron, Sen. Stuart Symington (D-Mo.), Helms testified in February, 1973, that the CIA played no role in passing money to or helping opponents of the late President Salvador Allende in Chile, later disclosed to have been the target of an undeclared covert war by President NixoN. The following March Helms made similar disclaimers to the same committee, then headed by former Sen. J. W. Fulbright (D-Ark.), another staunch Helms partisan.

Throughout his ordeal Helms professed to have been obeying a higher loyalty - the code of his craft, his oath as an intelligence operative. He felt, as he put it yesterday, a position "of total conflict" between his obligation to keep institutional secrets and to obey the law which binds all of us.

For Carter, who campaigned for office against the excesses of the intelligence establishment and in behalf of an "open" administration, the Helms case must also have posed a painful dilema.

For the men charged with prosecuting the case, Attorney General Bell and his deputy in charge of the criminal division, Benjamin R. Civiletti, the horns of the Helms dilemma bit as deeply as anywhere in the government.

Williams had made it clear that to defend Helms against such prosecution it might be necessary to open up national security issues which could be profoundly embarrassing to the government - even to some of those personages who had escaped the tar brush of the case. It was for this reason, as Civiletti argued in court, that the administration had chosen to initiate the plea-bargaining with the former CIA director.

For Barrington Parker, the independent-minded black judge who was born in Rosslyn, Va., and educated in the District of Columbia schools, there seemed to have been no ambiguities, no anguishing.

"You now stand before this court in disgrace and shame," he told Richard Helms yesterday.

As he uttered these words Richard Helms gripped the podium with tense fingers. The patrician achiever, who had made Phi Beta Kappa and class president and was voted "most likely to succeed" at Williams College - and did - had come to the climax of his ordeal.

And in a way, so did the institution he served since the CIA was constituted 30 years ago, when Helms first went to work there.