Many things are permanent and relatively everlasting, but nothing goes on forever, and where I grew up in the Lower Mississippi Valley we all knew that. The great river itself once turned around and flowed to the north.

If the lifeline river could pick itself up and carve a new course miles away, or flow backward in an earthquake, and if we have evidence that high mountains were once beneath the sea, then we get some hint that things change and are not always what they seem. Every kid should learn about necessity, about rhetoric and about bull.

There once was an Irishman who returned from the market where he didn't get as much for his pig as he thought he'd get, but then he never dreamed he would.

In the same way, we are surprised at Bush's reversals, but then we knew we would be.

One of the many chancy areas of law covers actions for fraud. You can't be defrauded and claim damages (if one may speak in a general way; and remember I'm not your lawyer) if you never relied on the fraudulent promise in the first place. Furthermore, you may have trouble collecting damages even if you did rely on the fraudulent promise. If the promise was so obviously false that no reasonable person would believe it, the courts may not help the victim out.

As humans, we like to be fooled up to a point. We love riddles that seem impossible to solve and then the answer is stunningly simple and simple-minded. Some of those papers sold in checkout lines rely on marvelous come-ons in the headlines, to get you to buy the story. It is a pleasant exercise to read the story and see how long it takes for the whole headline promise to collapse. Usually four paragraphs.

There was a headline in one such publication, "Deranged Tot Rapes Nun," and I regret I saw only that headline. I still wonder how the story worked out.

We are singularly blessed in our country by advertising messages, many of which are bald lies, but it's all right because we call it puffery and the normal enthusiasm of any seller for his soap, spray, or scheme for perfecting the world.

As a result, we should be better prepared than the folk of any other nation to discount every statement we hear when the speaker is promoting the bee in his bonnet.

And yet no people surpass us at being stunned when it turns out Donald Trump is not really as securely rich as we thought, that Mayor Barry is not really as opposed to drugs as he said he was, that George Bush is not as rock-hard against new taxes as said. Whatever is being sold big is after all being sold by someone who puts his pants on one leg at a time and probably takes them off the same way. Nelson Mandela, who has suffered much for liberty and civil rights, may have to bat an eye at the practices of some of his great friends in Libya and Cuba.

We call this necessity. The truth is we are all saints except when necessity moves us a bit toward the Devil, and we differ only in how often and how soon we hear necessity singing.

Some have asked why Barry did not use his bully pulpit to argue for the legalization of drugs, instead of running about full throttle on how terrible drugs are.

But don't you see, if he argued that drugs are not all that bad he would never have gotten elected. He would not have been able to serve the city, a necessity even though he gave too much of himself as he says and just wore himself out. It was necessary to preach one thing and do another, and it's not just politicians who learn the art.

Cardinal John O'Connor has pointed out that a Roman Catholic politician should remember the church's position on abortion, and the logical possibility that excommunication might fall on a member who flouts papal teaching. This inspires Gov. Mario Cuomo to claim a certain sorrow and distress, because of course he deeply respects the cardinal. I do not hold my breath awaiting the excommunication of a national political figure, and I do not bet large sums on the governor's obedience to any authority if he thinks it interferes with his governing.

Eternal values naturally remain eternal values, though of course they change as necessity requires. It is unthinkable for a president to mislead his own people. Roosevelt promised not to take the nation to war, Eisenhower denied there was any U-2 plane, Johnson painted false pictures of the Vietnam War, Reagan promised to cut big-government costs, Bush promised no new taxes.

This business by which necessity makes liars of most of us has always bothered the tenderhearted. The transience of all things, from youthful beauty to high-sounding political positions, is such a commonplace that while we may sigh we should not throw a fit of astonishment.

Not even gates of steel are proof against the rust of time. New ages, new insights, new errors, new under- standings. Always change, in traffic patterns or availability of divorce.

Even in good times you have to ask how will summer's honey'd breath hold out? Whose action is no stronger than a flower, as the poet says.

Ha. No stronger than a flower. But it's the flower that renews itself and is around when the monuments have rusted out.

We have this itch to go whole hog. We take up some enthusiasm and run with it. We insist on attributing to some person an almost divine virtue, as if a degree in philosophy or a choice of trades, or an election by a lot of people who have little choice to begin with, somehow makes that person the ultimate good guy. But it's still one leg at a time.

Walt Whitman once wrote that he "could turn and live with the animals" because they are so free of baloney.

But there's your problem. We are animals. Fairly disgusting ones, often enough. That's what dogs are for, to redeem the good name of beasts.