On the eve of the U.S. invasion of Grenada, White House reporters asked presidential spokesman Larry Speakes if American troops were about to invade the island. The questions had not come out of thin air. Grenada was in chaos, American medical students there seemed to be in danger, and U.S. ships had been sighted in the vicinity. Speakes gave an unequivocal answer: No. The next morning, U.S. troops hit the beach.

It was later revealed that Speakes himself had been misinformed about the invasion. But let's suppose that he had lied. Was he entitled to? Lots of people, especially journalists, would say no. They argue that truth is the foundation upon which democracy rests. Citizens cannot make informed decisions if they are misled. So great are the stakes that lying to the press, which is lying to the people once removed, cannot be countenanced. This standard permits no exceptions.

On the other hand, the United States was indeed preparing to invade Grenada. Lives were at stake. Was it in the best interest of the United States -- Was it in the best interest of the troops? -- for Speakes to tell the truth? Could the White House press corps be trusted to keep the secret? Could the government take that chance?

A friend of mine, educated by the Jesuits, tells of a problem put to him as a schoolboy. A gunman, intent on killing a certain person, bursts into a room and demands to know where he can find his intended victim. The people in the room know where that person is. Do they have to tell the truth? Most people would say that under those circumstances, a lie is permissible. If that's the case, why then was Speakes held to account for lying under approximately the same circumstances?

The answer, I think, has to do with the fact that journalists have emerged as today's ethicists. The press is the institution that, more than academia or religion, sets ethical standards for public figures. In the past, the people who tussled with moral and ethical issues were scholars and theologians -- sometimes cloistered, often otherworldly men who frequently decided questions in which they themselves were disinterested. (Moral questions involving sex and marriage are even today decided in the Roman Catholic Church by a celibate clergy.) Journalists, though, have a professional stake in truth. It is their product, what they sell the public and, maybe just as important, a touchstone by which they judge the people upon whom they rely for information. Thus, a press secretary must never lie. His credibility is all he has going for him.

So, maybe for reasons of self-interest, and not just the furtherance of democracy, lying has been invested with a gravity it once did not have. The power of the press is such that few dare argue with it. Take the case of Jesse Jackson. Asked by The Wall Street Journal if he were "an adulterer," Jackson did not say no. Instead, his spokeswoman issued a formal statement that, in effect, said the question was out of bounds and the answer immaterial to Jackson's presidential bid.

I happen to agree with both assertions, but, even so, the standard response to such a question used to be "no." But a "no" could violate the new rules, which hold that lying about adultery is worse than adultery itself. In fact, the Cleveland Plain Dealer reported Ohio Gov. Richard Celeste's affairs only after Celeste was asked at a news conference if there was anything in his personal life that might preclude his being president "in the same way as it had Gary Hart." Celeste said no, and the denial triggered the story. Indeed, the Plain Dealer's executive editor, William Woestendiek, justified the story by calling Celeste's denial "absolute arrogance."

Now take the case of John Sasso. The former campaign manager for Michael Dukakis leaked a so-called "attack tape" that showed Sen. Joseph Biden plagiarizing a speech. Sasso denied that leaking the tape was his work, which, of course, he was obliged to do. After all, a leak is not a leak if the person doing the leaking takes credit for it. But Sasso was forced to quit -- not only because he had leaked the tape, but also because he had lied to the press about leaking it. It was hard to tell which was the more grievous sin.

Interestingly, lying in and of itself is not what concerns journalists. It is only lying that victimizes them. For instance, it has long been accepted that a person who has leaked information to the press is entitled to say he did not. He can lie to his boss and his colleagues and no journalist will think the worse of him. But should that person lie to a journalist, then grave questions of credibility and character are suddenly said to be at stake.

The thinking that the lie is more serious than the act it seeks to conceal, while self-serving to journalists, is reinforced in the popular mind by Watergate. In that case, the cover-up was in fact worse than the petty burglary that preceded it. But lying, while always a serious matter, is not a litmus test that tells all about a person, that supplies the one true answer to complex questions about character.

Sometimes there are good reasons to lie, sometimes merely understandable ones, sometimes unavoidable ones. Journalists who declare that all public lies are the same, who don't ask why the lie was uttered and what, if anything, it says about the liar, apply a standard that they would not like applied to themselves. We all lie on occasion. And sometimes it's the occasion, not the lie, that matters most. ::