MESSAGE-ISM is different from masochism, which it sounds like, although it is hard to distinguish an overdose of the first from a terrible attack of the second. By message-ism we mean that unfortunately thriving brand of politics, domestic and international, which involves bombarding a prospective audience with symbols, signals, gimmicks, sight gags and assorted dumb photographs, such as -- if you need an example -- the one we have reprinted here. The senators -- get it? -- are wearing old-fashioned bookkeeper's eyeshades to communicate their determination to attack the federal budget remorselessly, in the manner of cost-cutting clerks. That, of course, is the federal budget they are holding. It says so right on the front. See? They are sending you a message -- or at least they were back in January when this picture was taken. This is message-ism pure and simple. Especially, simple.

We have exhumed this photo from our files because it so nicely sums up the condition of the nation's politics just now. Everybody, as it seems, is sending everybody else these little picture post cards by way of proving a point or asserting a position. From them you are meant to take the desired message. Thus we read the other day, for instance, that President Carter had sent his son Chip on a delicate mission to Saudi Arabia and Jordan with National Security Adviser Zbigniew Brzezinski, Deputy Secretary of State Warren Christopher and the chairman of the Joint Chiefs of Staff, Gen. David Jones. This was his way, the explanations went, of demonstrating that the mission was personally important to him. Frankly, and meaning no harm to young Carter, we would have thought the three official emissaries quite august enough to have indicated that. The photograph of this eminent party plus Mr. Carter's son was, in our judgment, just uncomfortable-making, a real eye-averter, an embarrassment.

The master message-sender, of course, is not the president at all, but rather his antagonist in California, Gov. Edmund G. Brown Jr. He is the champion, and we say that fully aware of all the competition from those various politicians around the country who have managed to convey their sincerity and worth to the electorate by walking, running and doing handstands across their states and otherwise engaging in what are the newly acceptable and, evidently, successful forms of political shadow play. Gov. Brown of the little car and the modest lodging and that "favorite Mexican restaurant" where, so far as we can tell, he has a nightly jalapeno-laden (and "exclusive") interview going with some media hotshot or other, is a genius at exploiting these promotion techniques.

We're not suggesting that politics by pose and gesture is something new. In fact, the prototype of Jerry Brown may have been the elder Cato, who went on a comparable frugality and anti-pretension tear more than 2,000 years ago and who, on one of his missions abroad, declined to live in the official residence available to him for Jerry Brownesque reasons. We're not even saying that this kind of politics is wholly or irredeemably bad: Being able to use symbols powerfully and well is a useful, maybe even essential, element of governing. We are only saying (look again at that picture, if you need more convincing) that it has a silliness and turn-off potential as big as the Ritz, and that daily its manifestations seem to be getting more studied and un convincing -- and ridiculous.

These things, we note, are invariably undertaken by political figures on the theory that only such hokey message-sending will in fact get the message across. We have a feeling that the message is getting across all right, but not necessarily the one all those human transmitters have in mind.