WE WERE sitting around the other day doing what is known in more sophisticated circles as wargaming and brainstroming, and from time to time we even attempted a little prioritizing. The object of all this heavy thought was to work out some of the subjects and issues that should be addressed on this page and the next in the days to come concerning the two pending political conventions. We were somewhere between the morass of credentials fights and the swamp of platform economics when the technologically-minded one among us said: "Well, I have noticed that the ballons at Democratic conventions always float up while the balloons at Republican conventions always float down, and I would like to know why this is." There was sudden, awestruck silence in our group. Leave it to science to tear away the veil of subjective maundering and get to the heart of the matter.

The assertion is, of course, at least 82 percent empirically sound. Even as the devastating question was being put, the minds of the more political types around the room were being filled with that golden shower of downward-floating balloons that signaled the nomination of Sen. Goldwater at the fabled, if somewhat disagreeable, Cow Palace convention of 1964. The Nixon balloons (red-white-and-blue, if memory serves) also started from a cage in the sky and appeared to defy the laws of helium in their downward-sinking path. Whereas the Democrats' balloons -- vulgar, even gross, children's birthday-party colors, attended by a battlefield burst of of unauthorized popping -- tend to course heavenward.

Our first effort to come to grips with this leaned heavily on symbol and metaphor -- the superannauted English Lit majors' instinctive response in the face of any uncertainly or peril. Could the upward/ downward thing be Saying Something about, let us say, the Democratic promise of pie-in-the sky and the Republican commitment to trickle-down economic benefits? Much booing. Well, then if you're so smart . . . Another metaphorical pass or two was made at turning the rising and descending balloons into substitutes for soaring profits, the Decline of the West, and so forth, but it was the consensus of all that this wasn't quite it either.

This weekend's newly disclosed political polls may provide a clue. The fantasitc resuregence of the Republican Party in the course of a Democratic administration, equaled only by the gains the Democrats make when Republicans are in office, tells us something. It is that the best way a rise in public esteem, if you are a political party, is not to be in office. There is something synergistic here, something coordinated, something push-pull, something almost perfectly and beautifully expressed -- as is nature's way -- in the image of the ballons perpetually floating up . . . and down. It is rhythmic, peaceful, like an ocean tide or a pendulum, never mind that the principle seems to be not so much a self-righting as a self-destroying one.

Even though we haven't divined it yet, we have no doubt that there is some natural principle at work here. For example: What goes up must come down. It takes two to tango. The ratio of the potential difference between the ends of a conductor and the current flowing in the conductor is constant. Fish gotta swim, birds gotta fly. Something like that -- we're working on it.