The Supreme Court's traditionally strong distrust of government attempts to impose prior restraints on speech or publication may face its most severe test as a result of the Progressive magazine's effort to publish an article entitled "How a Hydrogen Bomb Works."

When the material at issue was history rather than thermonuclear weaponry, as it was in the Pentagon Papers case in 1971, only six of the nine justices voted down the Nixon administration's efforts to prevent newspapers from publishing the documents.

In agreeing with the majority, Justice Potter Stewart suggested he was doing so because "I cannot say that disclosure will surely result in direct, immediate, and irreparable damage to our nation and its people." Justice Byron R. White added his signature to Stewart's opinion.

If the Progressive case should reach the court, Stewart and White will be confronted by a government claim -- disputed by the Progressive -- that the proposed article "is of current military significance to any nation attempting to develop a hydrogen bomb capacity," including "present and potential enemies of the United States...."

To be sure, there will be counter arguments of the kind made coincidentally, in the March 10 Nation magazine, by Thomas I. Emerson, Lines professor of law emeritus at Yale. In his view, the irreparable damage standard is "unconstitutionally vague," because no one -- not the press, ordinary citizens, prosecutors, judges, or juries -- could know in advance how to comply with it.

Even so, the chasm in subject matter -- between history and H-bombs -- remains.

In another Pentagon Papers opinion, White, joined by Stewart, said he concurred in the judgment of the court for an additional reason: the government had secured an injunction to bar publication when the law in question didn't authorize injunctions.

By contrast, the Atomic Energy Act of 1946 specifically provides for enforcement with temporary restraining orders, and then preliminary and permanent injuctions, whenever the Department of Energy (a successor to the Atomic Energy Commission) judges that "any person has engaged or is about to engage in any act or practices which constitute or will constitute a violation..."

Again, there are counterarguments, particularly that Congress may not have intended to let the government seek to enjoin "publication" by a news organ as opposed to "communication" to say, foreign agent.

The stark difference that might be crucial to Justices White, Stewart and possibly other members of the court remains: the law in the Pentagon Papers case didn't authorize injunctions; the atomic energy law does.

The 1971 majority included Justices Hugo L. Black and William O. Douglas. They stood for the proposition that the First Amendment's command -- "Congress shall make no law... abridging the freedom... of the press..." -- means, as Black put it, "that the press must be left free to publish news, whatever the source, without censorship, injunctions, or prior restraints."

Black has died. Douglas has retired. Their successors do not share their unequivocal views. The chief justice of the United States, Warren E. Burger, wrote in 1976, "The extraordinary protections afforded by the First Amendment carry with them something in the nature of a fiduciary duty to exercise the protected rights responsibly -- a duty widely acknowledged but not always observed by editors and publishers."

Yet Burger, too, has been emphatic in expressing the high court's traditional distrust of prior restraints, which it first expressed in deciding a 1931 case called Near vs. Olsen.

Terming prior restraints "the essence of censorship," the court said then that "it has been generally, if not universally, considered that it is the chief purpose" of the First Amendment to prevent their imposition.

For that reason, the court said, the protection against such restraints, while "not absolutely unlimited," can be breached only for "exceptional cases."

The court hewed to this almost-never policy through the years, saying in 1963, for example, that any prior restraint on expression comes to the court with a "heavy presumption" against its constitutional validity.

The 1971 Pentagon Papers decision was the first to raise directly the issue of a federal government effort to prevent publication of material by a newspaper.

The Supreme Court decided the case by citing the 1963 "heavy presumption," saying that the government carries "a heavy burden of showing justification for the imposition of such a (prior) restraint," and holding that the government hadn't carried the burden.

The question now is whether the Progressive case ultimately will be carried to the high court. If it is, few persons knowledgeable about the court would bet that it would find it unconstitutional to enjoin publication of an article on the innards of an Hbomb.