Here we sit in the most talkative town in the world -- press leaks and counterleaks, microphones stuck in faces that immediately start babbling, position papers till you could scream -- and still we never seem to know anything. How can this be? The question began to gnaw at me as I watched the Iran-contra hearings last week. Why is it that we seem always to end up needing boards of inquiry to tell us what just happened -- boards, by the way, that often end up needing subsequent inquiries to look into the reliability of their own findings?

One answer, of course, is that a lot of officials lie. You can begin to deal with this by not automatically assuming they are telling the truth (in case there is anyone left in the country who still makes this assumption). After that you have to rely on the simple human-plausibility test. This is less respectable but more reliable than all those pieces of (occasionally doctored) paper that men with artful haircuts are forever handing each other in formal proceedings and describing as "the evidence."

The human-plausibility test is nothing more than asking yourself whether people behave the way these people are alleged to have behaved in the version of events being put out. Elements of the Warren report, the Chappaquiddick explanation, the Watergate cover stories all fell prey to this. You come upon these parts of the story and, even if you have a will to believe, you find yourself saying: I don't know what happened, but this didn't happen . . . it's not the way people react, not why they do things, not how life works. I realize we are talking sworn testimony in the Iran-contra hearings here, and I am not in a position to charge anyone with under-oath lies. But I will say that much of the basic account of what happened that one is now asked to accept gives me big problems on the plausibility meter.

I'm referring to that whole scenario of how the one lone incriminating document unaccountably escaped Oliver North's voracious shredder and how, like Moses in the bulrushes, it miraculously survived and was spotted and saved by a passerby -- or almost a passerby, anyway: a Justice Department official who was looking for something else. I'm referring to this as the purported starting point of an investigation in which, as reported and fitfully recalled, key participants seemed to spend a great deal of time together or on the telephone without ever asking or discussing any of the obvious questions that would have come up at once if they had been as agitated as they claim to have been. Judged by human-plausibility test standards it is an absolutely nutty narrative. Ah, yes, but "truth is stranger than fiction," it was being defensively said and written in Washington last week. I have a revolutionary theory: fiction is stranger than truth most of the time, at least in the Washington-testimony field, and this is something people can tell without sworn oaths and polygraph tests and all the rest being administered to the narrators.

The same simple test, in my view, could be applied to all those people who have been called on to testify in the past few weeks. Make no mistake: the testimony itself has been astonishing, perhaps unprecedented, in its provision of inside information and detail. I don't know how good old executive privilege -- which I think is a legitimate concept with a legitimate function in some circumstances -- is ever going to survive this total rout. We have been treated to the most comprehensive he-said-then-I-said accounts of presidential business that I can remember. Surely when you were watching this you could sense right away and throughout what was authentic and what was not. Your own daily experience directed you here. Interestingly, Donald Regan, who in office was spectacularly unloved, seemed plausible, real. It was not an inspiring story, but you had a feeling that at least things could have happened that way, and, as with some of the others, his emotions and responses seemed genuine.

The best -- the purest -- illustration I can give of how the plausibilitytest works with individuals harks back to the Republican convention of 1980, at the end of that day when therewas so much turmoil and excitement over the effort to get Gerald Ford on the ticket with Ronald Reagan and when Reagan himself finally came to the hall to end the speculation. He didn't say, as so many of his predecessors most surely would have, that there had been no truth to therumors or that it was all the media's doing or that he had always beenfor George Bush, etc., etc. Instead, he said the rumors were true: theyhad tried but couldn't work it out, so he was turning to Bush who he thought was a helluva guy. It was amazing. The politician's version of the potentially embarrassing story squared with what you knew had happened. It disarmed everyone and did Reagan's political persona much good.

That distant moment makes another relevant point about today. It reminds of a time when, whatever you may think of Reagan now or did then, the press was discovering that he was not the particular caricature in the particular political scenario -- or, more precisely, fiction -- so many of us had conveniently imagined. For better or for worse, he was someone different from that. We of the press, in this current drama, have something to answer for, too. Too often we react reflexively to the predominant theory or official voice in a merely contrary way and mistake this automatic contrariness for insight. But insight doesn't come so easily. Like everything else in life, it, alas, takes work. Example: when Admiral Poindexter was named to the National Security post at the height of our collective contempt for the turf-grabbing Don Regan, we made a great issue of whether Poindexter would be allowed to report to the president directly or not and, God help us all, he apparently was. I'm not saying we made this happen -- only that we didn't know how to think about it.

Information overload, baloney overload, cliche' and superficiality overload -- the only things you can bring to the current proceedings in Washington are these: your best instinct, your common sense, the ever-trusty plausibility touchstone. Think about these witnesses. Consider closely what they have been saying these past few weeks. Measure them humanly rather than politically. You Will probably be able to figure it right.