An unlooked-for lesson in constitutional government emerges from the fascinating case of Myron Farber and The New York Times. It teaches all of us in the media that constitutional rights and privileges must be invoked in the spirit of selfdoubt, with a decent respect for the rights of others and a full sense of the especially delicate role played in our system by the judiciary.

Farber, of course, is the investigative reporter for The Times who did such a notable job in probing a dozen mysterious deaths that took place at the Riverdell Hospital in Oradell, N.J., in 1965 and 1966. The articles he published in The Times a decade later led to the indictment of Dr. Mario Jascalevich on charges that he murdered five of the patients by administering doese of curare

Lawyers for Jascalevich subpoenaed Farber's private notes on the grounds that the material was absolutely essential to preparing their client's defense. Farber and The Times refused to bonor the subpoena. They argue that turning over the notes wholesale compromised sources in ways that restricted the future flow of information, and thus violated First Amendment protections.

A compromise probably could have been struck if the trial judge, William Aronld, had made the defense stipulate particulare material that is regarded as critical to the case. Instead, Judge Arnold forced a confrontation.

He ordered Farber and The Times to turn over all the notes to him for determination as the whether they were pertinent. When The Times and Farber again refused blanket disclosure, they were cited for contempt. The paper and the reporter then moved to stay the contempt judgment in numerous appeals to other courts in New Jersey, where the deaths took place, in New York, where Farber lives, and in the U.S. Supreme Court.

In those hearing, lawyers for the paper argued that even turning the materials over to a judge for secret inspection in chambers was a violation of the First Amendment's assurance of a fress press. The plea of The Times to Supreme Court Justice Byron White, for example, said:

"The judiciary, after all, is a branch of government . . . and to hold that a member of that branch may view even in camera the confidential materials for which we seek First Amendment protection is to deprive the press immediately of such protection."

That plea has been repeatedly rejected by all judicial authorities, and not surprisingly. For while it is true that Faber and The Times have rights under the First Amendment that by extension may include protecting sources, it is also true that Jascalevich has constitutional rights regarding fair criminal procedure. When those two sets of rights come into conflict, the final word as to which prevails falls, under our system, to the judiciary.

Exhibit A in that regard is a Supreme Court decision applauded by The Times and almost everybody else in the press and television. I mean the decision of the Supreme Court that dictated that President Nixon had to turn his tapes over the Watergate prosecutor. As that case shows, and as many others demonstrate, the judiciary is not - as The Times lawyers claimed the its editors asserted even more volubly - just another branch of government. It is, for better or worse, the branch of government quintessentially responsible for adjusting conflicting constitutional claims.

In the course of the appeals against the contempt decision, moreover, there was added a new element. It developed that Farber has a lucrative contract to do a book on the case. In other words, there is at stake an enterpreneurial element, a profit motive.

Thus what was originally presented as a pure question of First Amendment rights turns out to be very clouded indeed. The rights of the press under the Constitution have, in this case, to be weighed against the rights of a defendant in a murder trial. The judiciary is the obvious place for balancing out these conflicting rights, and its responsibilities in that respect are far more basic to the preservation of freedom than unfettered journalistic enterprise. The more so when journalistic enterprise turns out, as it often does in this era of the TV network and powerhouse press, to be married to mamon.

None of this gainsays the importance of a free press to the democratic government. The unimpaired flow of ideas is absolutely essential if citizens are to make the decisions our system demands of them. But precisely because the First Amendment is so precious, just because it is centreal to the workings of our system, it ought not to be invoked in doubtful - not to mention losing cases.