In some of his impromptu appearances, the president describes himself as "an old ex-horse cavalryman." Last month, for instance, when he stood on the navigation bridge of the USS Constellation, he said, "This is really kind of an earth-shattering experience for me, since my military service was as a horse cavalryman."

It's true he did serve in the cavalry reserve during his radio announcer days in Iowa, but not in the military service sense he implied. Since his service basically consisted of making training films for the Army Air Corps while assigned to the Hal Roach Studios near Hollywood during World War II, a war that found no need for horse cavalrymen, the expression stands as a harmless bit of presidential hyperbole, a not uncommon occurrence among the breed. Lyndon B. Johnson far exceeded him in such political arts. LBJ, who made one reconnaissance flight over New Guinea during that war on a special fact-finding (spelled political) assignment for Franklin D. Roosevelt, always liked to say he "knew what it was to be in combat."

With Ronald Reagan, the point is not the hyperbole, but what that sort of remark tells us about his view of himself, and, in fact, ours of him. In numerous films he was, of course, a horse cavalryman, boots, sabers and all. To the public, that celluloid image forever stamped this son of the midwestern plains as the simple Western hero, the good guy, whether cavalryman or cowboy, riding off into the sunset.

It would seem he holds something of the same view of himself, and perhaps accurately.

I say this not in a debunking, iconoclastic sense, but out of a certain puzzlement.

For decades Reagan has been one of our more familiar faces, and now he stands as the world's most widely examined figure. Despite all the attention, he remains strangely remote. It's not that he hasn't been consistent in articulating his political beliefs. Probably no other politician in our history has been more so. Nor is it that people lack a strong personal impression of him: his self-deprecating, head-cocked, aw-shucks manner of modest and compelling decency now is part of American folklore.

The puzzle arises over what Reagan really thinks. Is it all as clear as it seems, or is the artlessness part of the art?

For someone who has set off such a momentous national debate about his presidential course, all in only eight months, the public record of his activities remains surprisingly slight. He has spoken to the nation five times, all on the same subject of the economy, and held three news conferences. The rest of his public appearances consist of occasional political performances at some convention or fund-raiser, and a number of what can be described best as "drop-in-and-say-a-few-words" events before selected groups in the White House.

Go back and read the public record of his presidency thus far, as recorded in the official "Weekly Compilation of Presidential Documents," and you'll find the same themes over and over.

He quotes Calvin Coolidge on the efficacy of cutting taxes, invokes the volunteer spirit of a simpler day and inveighs against bureaucracy just as he did, and in the same phrases, during his campaign and in all the years leading up to his successful presidential race.

"We have silenced bureaucrats," he tells a New York City audience.

In Texas, he tells the Jaycees: "You believe in America and so do I. And I believe that your Jaycee spirit has become the American spirit. It's even making inroads on one of the most remote, protected areas of our country: the federal bureaucracy in Washington."

In California, and other places, he warns against "the advocates of a different philosophy who are manning the barricades in these puzzle palaces on the Potomac." He says he believes "most of the screams of pain that we're hearing are coming from the bureaucracy and not from the supposed victims of the cuts."

Everywhere, he expresses absolute certainty about the wisdom of his actions:

"We've done more in a shorter period of time to put the economy of this country back on a sound footing than any government in the past 50 years."

And:

"It's economic nonsense to say that lowering the tax rates will add to our deficits."

In one speech, he sums up his philosophy in the words of the Tin Pan Alley song written just after the U.S. entry into World War II: "We did it before and we can do it again."

Certainly, people respond positively to such expressions, and would like to be able to share his unbounded optimistic beliefs. Now, though, as hard questions are being asked about the soundness of his policies, something more than homilies may be needed to achieve the consensus he seeks.

Seeing the president close up, albeit briefly, reinforces these impressions--and questions. He came into the Roosevelt Room in the White House Friday, with Sandra D. O'Connor at his side, to say hello to a group of columnists and TV commentators being briefed during a "working lunch" with budget director David A. Stockman and Treasury Secretary Donald T. Regan.

All the familiar Reagan attributes were apparent immediately. He exudes an earnest charm and graciousness. He looks remarkably well: ruddy-faced and trim, relaxed and in fine humor. He handles the little introductions and greetings with an appealing light touch and sincerity. But when the few questions come, the impression is less clear-cut.

He says his feet are not set in concrete on Social Security cuts, one reporter notes. Could the same be said about possible cuts in his defense budget? His reply is ambiguous. Yes they are set in concrete, but then maybe not entirely. If Caspar W. Weinberger, his defense secretary, "can find additional places to cut where without setting back the plan that we believe is essential, that he'll bring them in."

Does that mean, another reporter asks, if Congress passed a bigger cut than he wanted he would veto that legislation? Again, an ambiguous reply: " . . . I'm going to veto budget-busting proposals that might come down, but I would have to see what they were based on and what it would eliminate in the program on a specific question."

Another question: how does he plan to fight what could be his most formidable foe--the public perception, as some critics have charged, that his economic program is one of mean-spiritedness and of starving some children? "We're fighting it because, again, I think there's something demagogic in that kind of a tactic. What we've found is that that program, like so many others, has enlarged and spread to where it's providing for people who have no reason to be receiving public help, that have a level of affluence that they can provide without that help, and this is what we're trying to eliminate."

Then, moments later, after saying he's got to take a telephone call ("a real phone call") amid laughter, a wave, and a renewed sense of good will and cheer, he leaves.

Think of other presidents in the modern era of American politics going back to Roosevelt. With the exception of Jimmy Carter, and to some extent Gerald R. Ford, strong personal images and adjectives are evoked. They are purposeful, cunning, steely, devious, feisty, stubborn, witty or tough, to use some of the words that come to mind.

For me, at least, Reagan conjures no such terms. One word springs forward to describe him. Nice.

If that impression has any validity, then the question arises: is being nice what American needs for the 1980s?