I overheard them only because I am compulsively on time in a world of Johnny-come-latelies and because restaurants are as private these days as the streets of Hong Kong.

The two men were drinking white wine and speculating about marriages. That in itself wasn't unusual because speculation is everyone's favorite indoor sport. It is a chic form of gossip when mixed with psychobabble.

But because it was Washington and lunchtime, the two sitting at the table next to me weren't talking about just any marriage. They were analyzing the private lives of public people.

To be utterly and painfully specific, they were delivering certainties about the relationships between Juanita Kreps and her husband and Teddy Kennedy and his wife.

I will spare you the details. But let me just say that before the white wine was consumed and the menu read, blame was assessed, personalties analyzed and the most intimate knowledge of these people's lives assumed. Were they friends of the Krepses, of the Kennedys? Not at all. Their theories were based solely on what they read in print. Plus, of course, gossip and psychobabble.

Well, after five minutes of glibness dropped over the eaves or the edges of the table, I sat fuming, fighting a compulsion to lean over and bellow: "How the hell do you know what goes on between two people?"

I am not going to launch into a holier-than-thou diatribe against speculation. To a certain extent we all do it, and not always unkindly. Friends leave our dinner parties and we chat about them idly while we do the dishes. People at work split and we decide why.

Those of us who are slick at it can sort the evidence and draw a brief in no time, building sound cases out of people's lives, loves, motivations.

But the fact is that we often confuse glibness with The Truth, especially when we deal with distant public figures. Today Washington is our Hollywood, the Senate our Warner Bros., the White House our Beverly Hills. People who never read a line of a movie magazine deal with the lives of leaders as if they were Elizabeth Taylor and Richard Burton. We talk about What Everyone Knows, instead of what no one can know.

It seems to me enormously difficult to really comprehend what goes on between two people, whether they are the Joneses or Jerry Brown and Linda Ronstadt. (It's even hard if you are one of the two people.) But it is virtually impossible to draw simple conclusions, single meanings from people's private lives.

Private lives don't conclude. For every set of facts there are a dozen possible meanings and for every event there are multiple sets of motivations.

What does it mean when one spouse becomes successful and the other attempts suicide? Does one person's problem force the other to be strong? Does one person's strength threaten the other into weakness? Are these facts even remotely related -- as my glib luncheon neighbors assumed?

In the same vein, how do people assess blame for an estranged marriage? Is it one spouse's apparent meandering, the other's confessed drinking, the chicken, the egg, or the unknown? Knowing "so much," we know far, far too little to make judgments.

What does it mean, for example, when a man is called a "womanizer"? That he likes women or hates them? That he is bringing pain to his wife or that both agreed to separateness?

Is one staying married out of loyalty, the other out of weakness; one out of hope for reconciliation, the other out of religious belief? What mix of emotions do we so blithely unscramble and assess? What do we pretend to know?

I am uncomfortable even raising these issues, because inevitably talking about gossip becomes a form of gossip all its own. It is rather like all of the politicians so studiously telling us how they will not talk about Chappaquiddick.

But I think it is important because it seems to me already that this is the year, and surely this will be the campaign, of speculation about what we so delicately, insinuatingly refer to as "private life."

Privacy will be invaded and maintained. Gossip and psychobabble will rule. Meaning will be sewn out of scraps of facts labeled authentic by their designers. People in restaurants and living rooms will draw conclusions about private scenes from a marriage or two, and it troubles me.

It seems to me that we have always been skeptical about facts. It's time to be absolutely squeamish about conclusions.