The Shakespeare passage that begins with the words "This above all" comes from Hamlet. Polonius, that "most secret" councillor, gives advice to his son, about to depart for a longer stay abroad. The three words entered my consciousness around the age of 12 - courtesy of Eric Knight (of Lassie fame), whose novel bearing that title makes for a special kind of acquaintance with England. Readers familiar with Shakespeare's "Richard II" or Baroness Orczy's "The Scarlet Pimpernel" would find it a worthy complement. But I digress. Here is the entire passage:

"This above all: to thine own self be true,
And it must follow, as the night the day,
Thou canst not then be false to any man."

The person eliciting these thoughts is not readily associated with Shakespeare quotes. Yet, especially these days, Rush Limbaugh brings those lines to mind in every one of the 15 hours he spends on the air each week.

For over a decade now, Rush Limbaugh has been a national institution. In that time, America's primary enemy has ceased to exist, the presidency has been trashed and restored, and once-noble Ted Koppel became a caricature of himself. Meanwhile, no effort has been spared to demolish Rush. His enemies are legion. They include everyone who, as Rush would put it, has no stomach for the truth. And, sadly, the number of those is steadily rising.

But, thank goodness, so is the number of opening minds. Nonetheless, as we speak, Rush finds himself under daily attack by some of his own constituency. Why? Because he remains true to himself.

In many ways, to understand Rush is to understand America. And if one understands America, it is easy to understand Rush. America, too, finds itself under daily attack by some of its own constituency.

Europeans greatly enjoy pointing out America's lack of "culture" in the sense that, in this country, literature and music and the fine arts do not occupy the central role they do over there. Being sufficiently familiar with high culture is not a social requirement here and, having come from Europe, I, too, found that something of a shock way back when.

But what really irks Europeans is that this "under-cultured" society not only commands incomparable economic and military power, but that it has succeeded as a society like none other. How dare they!? More importantly, how could they, spending so little time on debating political philosophy, and all those cultural ingredients that generate intellectual excitement?

Well - for almost two centuries, the debate here was only about the implementation of basic tenets, laid down by the Founding Fathers and agreed to by all who lived or came to live here. There seemed to be neither need nor appetite for meddling with them. They worked. Americans like things that work. And Americans like to work. Perhaps they like to work because, for a long time, the fruits of their labor were theirs to keep.

Then, about 30-35 years ago, the basic tenets started to be questioned. But many continued to believe in them, and those millions developed a very uneasy stomach as they watched the news or current affairs programs on television, and listened to National Public Radio.

Amazing as this may be, one person was able to change all that and restore sanity. Rush Limbaugh had to be, and is, as American as anyone might hope to be: straight-forward, practical, realistic, task-oriented, independent, enterprising, hard-working, good-natured, good-humored, and someone for whom defeat is not an option.

In fact, his radio show easily divides the population of this country into those who are staying with America's founding principles, and those who advocate - or unwittingly accept - the idea of trying everything under the sun that has already failed many times, in many places. (No, this time I won't call it socialism.)

In recent days and weeks, Rush's consistency has been getting him some harsh admonishment from callers and correspondents - the reason for this article. People are upset when he agrees with the president (he mustn't), and when he disagrees with the president (again, he mustn't).

The likely reason is that people have lost their footing. With every passing day, it becomes more difficult to countenance the president's wholesale abandonment of founding principles in the name of election strategy. Should Conservatives advocate that the administration do the right thing for America now, or obey Reagan's 11th Commandment? And it is easier to vent one's frustration on a radio talk show host, than on the... Perish the thought!

Those who are true to themselves tend to fare poorly in confusing times. My former teacher Dohnányi, possibly the greatest Hungarian musician after Liszt, paid for his immutable stance amidst ever-changing political loyalties by having his name purged from history books under the Communist regime. All Rush is doing now is standing firm as the winds blow from every direction. No doubt, for this reason, and for others, there are many in this country who would stop Rush - if they could.

That they cannot - not now, and not for a long time yet - has everything to do with those American principles that Europeans cannot quite comprehend, and that Rush Limbaugh embodies and advocates. Strange: he was not required to preserve, protect and defend the Constitution of the United States, he just does it.

Our nation's capital is packed with folks who have furnished such an oath. Would that they implemented it half as well.