When the Reagan administration decided to seek jail terms for conscientious objectors to draft registration, I found myself wishing that these 18-to- 21-year-olds, in their crisis of conscience, knew about Dwight Macdonald. I doubt if many did. At his recent death at 76, he was a figure whose old- left rebellions seemed so far back in the '40s, '50s and '60s that he was the ancient left.

It's a deception. If any intellectual- radical-debunker deserves to be appreciated by today's young who have more venturesome goals than obedience to the state or vanishing into the mists of suburban comfort, it is Macdonald. He spelled out in 1947--two years after America fought its supposed "good war"--the reasons for taking a moral stance against cooperating with military conscription.

The scene was a New York rally at which, with the police and the FBI hovering, 63 young men destroyed their draft cards. Macdonald joined them. "If it be argued that I am an American citizen and so have an obligation to 'defend my country,' I would note that my being born on American soil was quite involuntary and that I have not since signed any social contract. In such a serious matter as going to war, each individual must decide for himself; and this means civil disobedience to the state power that presumes to decide for one."

Such thinking cast Macdonald into what passes for extremist politics. Among his several books was one called "Against the American Grain." It was a grain that, as a writer for publications like The New Yorker, Dissent, Partisan Review, Esquire and The Nation, Macdonald sawed into with a style that was usually more wry than snarling.

His writing was as graceful as his politics were rambunctious. What saved him, time and again, were his afterthoughts. For a moment in the '30s, he liked Stalin, but then learned better. In 1942, he was arrested for picketing the Soviet consulate in New York in protest of the murder of Trotsky. Then he left that behind. In 1944, as the editor of his short-lived magazine, Politics, Macdonald sneered at the socialism of Norman Thomas. Fifteen years later, he praised Thomas as "America's conscience."

These goings and comings reflected scrappiness, not flightiness. He kept book on his own shiftings and was large-minded enough to admit publicly when he was taken in. About Lyndon Johnson and Vietnam, Macdonald said, "I mistook Johnson for another limited provincial like Harding, Coolidge, or Truman, but he proved to be both more and less: a monster, not a mediocrity."

A few years later, Macdonald said, "I made the same mistake about Nixon. I thought he'd be another do-nothing Eisenhower conservative. He turned out to be an active subverter and corruptor of our institutions. . . . But at least I didn't vote for him."

The catchword for someone like Macdonald is literary gadfly. But his writings and convictions had more to them than mere buzzings. In 1970, he was elected to the congressionally chartered National Institute of Arts and Letters. The tone of his radicalism was traditional, traceable to Thoreau a century before, to Eugene Debs a half-century earlier, and shared with such contemporaries and friends on the left as Dorothy Day, David McReynolds and Pete Seeger.

As a writer, Macdonald toiled in the George Seldes-I. F. Stone wing of American journalism. Independence meant not only no permanent attachment to an employer but no allegiance to an institutional credo. A British magazine once ran a Macdonald piece on America that was well short of a flag-waver. The editors, covering themselves, said the article wouldn't have been run "were not Mr. Macdonald himself a good American."

Macdonald, offended, wrote to the editor to correct the error, saying that he preferred to be called "A Critical American." Besides, he added, "A Bad American, cynical and traitorous, might still make perfectly sound criticisms of his country. And if they were sound, it would be your editorial duty to print them."

The number of editors who fulfilled their duties to their readers by printing Macdonald--regardless of the state of his Americanism--remained large for most of the past four decades. The benefit to Macdonald's audience was that his personal beliefs--especially pacifism--gave sure footing to his public opinions.