protective attitude stemming from a desire not to find itself without any leads for investigation of one of the most outstanding examples of how private citizens can reveal information that the government would rather keep in the dark.

Despite an opening statement by Popkin testifying that he had seen portions of the Pentagon Papers only after their publication in The New York Times and that he was not aware of any plans for publication or distribution, the grand jury repeatedly asked him about his involvement in both of these matters. Popkin repeatedly read the paragraphs from his original statement denying knowledge.

The grand jury, failing to obtain an affirmative answer of previous knowledge, then moved into the more nebulous area of opinion--did Popkin have an opinion on who might have had copies of the papers?

Popkin's questions on the relevance of these inquiries were repeatedly rebuffed.

But the jury pressed further. How were these opinions formed? Through contacts and interviews in line with his research on Vietnam, he replied.

Who were these contacts, the jury countered. Popkin repeatedly invoked a narrow definition of the First Amendment--protection of the identities of sources under freedom of speech, press and assembly.

It is for these First Amendment answers that Popkin faces a hearing on whether he should be found in contempt. "The prosecution's argument is based on the questions that I did not answer." Popkin said yesterday, "and not on those that I did answer."

He added that his attitude toward the Pentagon Papers was basically one of disinterest. "You don't find out anything about Vietnam from the Pentagon Papers--you find out about Washington."