Inauguration day: intimations of history still to be written. How will Ronald Reagan look, 10 or 50 or 100 years from now? Will marble tablets record: "He cut the rate of growth of federal spending"? Will our grandchildren recall in song and verse: "He conquered Grenada"?

No, Reagan's specific accomplishments don't yet look like the stuff of history. A domestic policy of cutting taxes and government programs does not leave much of a monument for posterity, and Reagan's foreign policy has not even left a mark on his contemporary world.

But a president's historical reputation need not be constructed from bills signed or treaties ratified. Reagan can take other possible routes to historic fame, some of them quite promising on this inaugural weekend -- provided his luck holds.

Reagan dreams of a place in the history books likeFranklin D. Roosevelt's. FDR is the only previous occupant of the White House regularly mentioned by the present one, and Reagan gives the impression that he sees himself in Rooseveltian hues.

The Roosevelt model is worth pondering. On one hand, it's hard to argue that FDR's policies were a great success; the New Deal did not end the Depression or undo its consequences (World War II did). On the other hand, Roosevelt restored the confidence of a nation whose depression was more than economic; he saved American capitalism in its darkest hour, largely by the force of his own personality.

That's the sort of accomplishment Reagan must dream of. Wouldn't he love to be remembered as the president who put the unhappy, divisive '60s and '70s behind us -- who restored American self- confidence and optimism and returned the country to its true historic path? And that sort of accomplishment may be within reach -- but only if his luck holds.

There's been a lot of talk about Reagan devoting his second term to assuring his place in history, particularly by achieving an arms control agreement with the Soviet Union.

But presidents don't have much control over their historical reputations, which can depend as much on events after they leave office as on their own apparent accomplishments.

Hebert S. Parmet of the City University of New York, a biographer of John F. Kennedy, remarked last week that Reagan might succeed in getting that arms-control agreement, only to see it vilified in later years as a "sellout," the way the Yalta agreements fell into disrepute. And of course, if nuclear weapons are used some day, all prior arms-control agreements will look ridiculous.

Trying to use a second term for historic accomplishments challenges the odds. Second terms rarely make history, except (as in Woodrow Wilson's case) when outside events forced the issue.

FDR's second term was something of a fiasco, remembered best for his intemperate attempt to stack the Supreme Court. Reagan's second term could also assume historic proportions for negative reasons. These next four years are the time when everything can go sour.

Will foreigners continue so generously to finance our huge budget deficits and our economic recovery? Only hundreds of billions from abroad -- an unprecedented movement of international wealth into the United States -- has preserved the low- inflation boom of the last two years. The flow could stop -- could even be reversed -- at any time, with potentially catastrophic consequences for the United States, and for Ronald Reagan.

The private conversations of Senate Republicans this past week offer a glimpse of nightmares that -- if they are realized -- could undo Reagan, his political party or both. We've had a funny few months of euphoria; polls suggest an exuberant national mood. But the senior Republicans in the Senate understand the dimensions of the Reagan administration's failure to find any concrete solution to the budget deficit, a problem that terrifies them.

A similar uncertainty emerges from the recent personnel changes in the White House, which offer the possibility of dramatically undermining the Reagan presidency. The laziest, most detached president of modern times has traded in a powerful staff of gifted aides led by James Baker -- himself one of the most talented and resourceful political operators Washington has seen in years -- for a stubborn 66-year-old salesman, Donald Regan, who has no record as a political operative, and speaks cavalierly of "hiring experts" to take care of political business for him in his new role as White House chief of staff.

A successful presidency requires constant political care and feeding. "It requires a campaign team" in the White House, observed David Gergen last week. During the first three years of the Reagan presidency when he was White House director of communications, Gergen was a member of the campaign team -- a team that has now been totally disbanded. W

illiam E. Leuchtenburg, a biographer of FDR and professor of history at the University of North Carolina, last week ticked off a list of half a dozen liabilities that Reagan carries into his confrontation with future historians from his first term:

* Reagan has no memorable accomplishments in the international arena. "You could write the diplomatic history of the 20th century and leave Reagan out at this point," Leuchtenburg said.

* The budget deficits. "We'll pay a price" for them eventually, he said.

* Future historians will be able to calculate the costs of Reagan's economic success up to now -- in unemployment, in enlarging by millions the population living in poverty, in damage to our finest exporting industries crippled by the overvalued dollar.

* Credit now given to Reagan for reducing inflation will, over time, be given to others as well -- to Jimmy Carter for his energy policies, to the collapse of OPEC, to Paul Volcker of the Federal Reserve.

* Reagan will lose points for his failure to do anything positive for the environment -- an issue, Leuchtenburg predicted, that will loom larger as the years pass and our environmental difficulties multiply.

* Reagan's appointments of mediocre men to important jobs will also be counted against him in future years, Leuchtenburg said. His cabinet won't measure up favorably to many others in the postwar era.

There's another liability Reagan carries into history from the last four years, his rhetoric. At every crucial juncture of his presidency, Reagan has been able to make a televised speech that vastly enhanced his position. Those speeches were tactical masterpieces, but history is more interested in qualities that go beyond tactics.

Look back, for example, at perhaps the most effective of those performances, Reagan's speech in the tense days after our Marines were killed by terrorists in Lebanon and we invaded Grenada. Barely 15 months later Reagan's words on that occasion smack of demogoguery:

"Let me ask those who say we should get out of Lebanon: If we were to leave Labanon now, what message would that send to those who foment instability and terrorism? . . . If terrorism and intimidation succeed, it will be a devastating blow to the peace process and to Israel's search for genuine security . . . . Can the United States, or the free world, for that matter, stand by and see the Middle East incorporated into the Soviet bloc? . . . Brave young men have been taken from us . . . . We must not strip every ounce of meaning and purpose from their courageous sacrifice." Is that what we did, a few months later, when we pulled out of Lebanon? It would be a lonely meeting at the Pearly Gates if Reagan had nothing else to bring with him to his confrontation with history. But in fact he has much more to show for his first term.

Reagan has restored his country's confidence, no small accomplishment after the demoralizing '60s and '70s. Every index of popular sentiment shows that large majorities of Americans feel much more upbeat after Reagan's first term. They even feel better about the government that President Reagan keeps telling them is their enemy.

Consider the responses to one poll question asked regularly over many years by the University of Michigan's Center for Political Studies: "How much do you think you can trust the government in Washington to do what is right -- just about always, most of the time or only some of the time?"

In 1964, a high point of confidence, 76 percent said they trusted the government to do the right thing all or most of the time. By 1980, just 25 percent answered the same way. By 1984, the number was up to 45 percent.

Reagan has demonstrated a remarkable ability "to identify with deeper national values," in the words of George Nash, an historian who is writing a biography of Herbert Hoover. Nash thinks this skill helps Reagan avoid personal blame for things that go wrong while he is president. It also helps the president reach out to segments of the population that were most alienated by the last 20 years.

Reagan seems likely to get credit for truly historic accomplishments in changing the national agenda. Washington greeted his plans to cut government spending deeply in many "soft" areas with profound skepticism, but Reagan routed the spending lobbies and rewrote political formulas that had prevailed here for a generation.

In the process, the president routed a school of thought that had been gaining many adherents in the previous dozen years by arguing that the modern presidency could never again dominate a national politics typified by powerful interest groups and emasculated political parties. Reagan's first term contradicted that argument.

The last four years offer at least the possibility that Reagan's presidency will be remembered as an historic turning point for the country's politics. We may look back at these years as the end of the New Deal era, and as the beginning of a period in which the Republican Party moved decisively away from its historic moderation to a more right-wing stance.

If the second term includes sweeping tax reform that puts the tax accountants and lawyers out of business, or at least diminishes their role, so many Americans will be grateful that the accomplishment will be remembered like many of Roosevelt's most important reforms.

And of course, if Reaganomics continues to bring prosperity -- if all the prognosticators of economic doom are proven wrong -- then Reagan's historical reputation will be golden. He'll be forgiven for failing to balance the budget if it turns out that big deficits don't have the bad consequences so many people (including, for years, Ronald Reagan) have contended.

Reagan carries another advantage into his meeting with posterity: his talent. The videotapes of Reagan's presidential performance will last forever. The human qualities that have made him so appealing to his contemporaries will survive in a form that Americans centuries from now will be able to appreciate (unlike, say, Lincoln's qualities, which are preserved only in written words). If the Reagan presidency becomes a Hooveresque failure, that record may make him a buffoon for future generations; but if his presidency thrives, so will his personal reputation. This accounting sounds contradictory, as it must on the eve of the second half of the Reagan presidency. All the important questions about Ronald Reagan's White House tenure remain to be answered.

Prof. Parmet of CUNY recalled last week the beginnings of his teaching career, more than 30 years ago. In the early 1950s, he said, he could count on getting a laugh from his students just by mentioning the much-maligned name of Harry S Truman. A symbol of failure, the object of intense partisan hatred, Truman left the White House in 1953 as a political basket case. But just a generation later he is an American hero, enshrined in the pantheon of successful and popular presidents. History is a fickle guardian of reputation.

Reagan's ability to smile through every apocalypse, shrug off every setback and be judged by an entirely new set of made-for- Reagan criteria may be a temporary phenomenon of our time. In this newspaper last Sunday, you read the revelation -- presented as newsworthy -- that during preparations for recent arms-control talks, Reagan took time out from his Sunday schedule to read an entire 17-page paper prepared by his aides; he even "made a large number of marginal notations." Does this mean we have a closet intellectual in the White House? No, but as FDR biographer Frank Freidel observed last week, "The will to believe in America is so wonderful!"

Perhaps the substance of presidential performance is less important than personal qualities like Reagan's. But if it takes more concrete accomplishment to really make history, this president could be at risk. He may see himself as a modern FDR, but the comparison is shallow. The New Deal failed to end the depression, but it transformed America, laying the groundwork for the society we have become. FDR's social welfare legislation, labor reform, banking and securities reforms and more remain monuments to an historic presidency. Ronald Reagan's cuts in the Women, Infants and Children program, or his selection of Ed Meese to be our attorney general, can't be put in the same category.

One last possibility. If Reagan succeeds in these next four years -- if he does preserve prosperity and peace in an era of good feeling -- might he then be remembered as the man who restored national confidence in the presidency? And might some future FDR, some exponent of the progressive and activist government that Reagan abhors, exploit that restored confidence to embark on a new progressive era in American history?