Somewhere in this city there might still be an old man -- very old now, I'm afraid--who I approached one day in a restaurant to advise that he was in violation of the "No Smoking' sign. The old man looked up, called me "Sonny," blew some smoke my way, and said, "It doesn't say 'positively.'" I learned something that day.

You will be forgiven if you don't think there's a lesson here, but there is. The lesson is not to see absolutes where there are none. The lesson is to enjoy, appreciate, and even thrill in, ambiguity--in the wonderfulness of fudge, in gray rather than black and white, in that most wonderful of all expression, the essece of the Talmud if not life itself: ". . . On the hand."

Here, in the most "on the other hand" of all cities, the Democratic Party is about to commit a sin. It is about to settle a question that should not be settled: the so-called question of an open or a closed convention. This is not a fight that needs to be fought. It is not an issue that needs to be settled. The word "positively" is not needed here.

The way it works now, delegates do not legally have to vote for the candidate to whom they are pledged. They just usually do. In fact, they almost always do. This is because they usually run pledged to a candidate and either believe in their man or simply wouldn't dare vote any other way. They have made a commitment -- a promise.

The proposed rule would leave nothing to chance. A delegate would either have to vote for the candidate to whom he is pledged, or be substituted. This raises the question of why you need delegates at all, but the answer to this is that someone has to wear funny hats, blow kazoos and talk to Dan Rather.

The issue is a total nonissue. It does not by itself change the outcome of the convention -- this one or any other. The way things stand now, most delegates do what's expected -- or get yanked. What gets lost is that very small opening, that itsy-bitsy sliver of personal option, that area of gray, of fudge, or unpredictability, or ambiguity, which to me and the old man at the restaurant is the essence of life.

After all, you can go either way on the issue. You could argue that by rejecting the rule and leaving the convention "open" you return to the dark days of the boss-ruled convention. It all sounds so terrible, but it's terrible nonsense, there being, for starters, no bosses left anyway. Or you could argue that by passing the rule, you turn the delegates into automatons. Again, nonsense.

What is not nonsense, though, is that as things stand now you don't have to reconcile the two positions. There's slippage here, open space, a contradiction like the one that exists between the right of a defendant to get hold of exculpaatory material and the right of the press to shield its sources. It is best to have no law for these situations. It is best to handle them on a case-by-case basis.

That is the case now with the convention rules. The door is left ajar. There is just a little bit of daylight and it exists for those rare occasions when that rare delegate, listening to his conscience and willing to take the consequences, simply does not vote for the person to whom he is pledged.He might, in fact, have a good reason for breaking his vow. His candidate might have been found to be a crook, a drunkard or merely have slipped in the bathtub, leaving him with a welt behind the ear and a mind that has turned to mush.

At the moment, though, nothing like that has happened. There is simply no reason to believe that a whole lot of delegates are going to defy tradition, break their promise, and not vote for the candidate to whom they are pledged. There is no need for the rule that would bind the delegates. All it would do is close off the little avenue -- a little outpost of conscience that should, like civil disobedience, be saved for a time when it might be needed.

In the meantime, the time has come to do nothing, to fudge, to consider -- as we must -- "the other hand": to save a little something for that delegate of conscience who will break his plege because he had to -- because, as the old man once explained to me, no one said "positively."