FOR A FEW anxious hours on that terrible Monday, it seemed, to borrow from the title of one of these books, that there might be no future under President Reagan. But that, happily, was not the case and, in history's perverse way, that would-be-assassin's bullet has, for a while at least, greatly enriched the president's political bank account. Even before that ghastly afternoon there was little to block the political and economic revolution (or should it be called counterrevolution?) Reagan brought to Washington.

The Senate was narrowly but firmly in Republican hands and in the House the born-again Republican/conservative-Democratic coalition of yesteryear made that nominally Democratic body far from unsympathetic to Reagan. Furthermore, the Democrats were divided and demoralized and, in the view of this longtime liberal Democrat, forever finished as an instrument of progressive and humane government. Thus, the stage was set for the kind of history reversal never before attempted in this country. Now, strengthened by the powerful flood of spontaneous sympathy, Reagan must be further encouraged to undertake his bold program of repealing history.

What course the president will pursue is the subject of these four books. The timing is a bit puzzling. If they had been published a year ago, they might have informed, or persuaded, voters before the election, but it seems a bit untimely to discuss the future of the Reagan presidency when, after the first 100 days, the nation already has a good idea what the president intends. That would seem to be, John F. Kennedy fashion, a renewal of the Cold War with a determined anti-Communist foreign policy backed by a marked increase in defense spending. The last time that culminated in the Vietnam war. Domestically, unlike Kennedy, the president has already taken steps to dismantle much of the New Deal and what followed, including programs that over a half century had become an accepted part of the nation's social fabric. What that will culminate in is too melancholoy to contemplate. s

There four books -- well, three of them anyway -- do shed considerable light on the future under President Reagan. The fourth, Frank van der Linden's The Real Reagan, is an extended puff piece, a reverent, even awed campaign biography that somehow came out after the campaign. Even so, there are some nice stories of Reagan as a boy and young man and an insider's account of that evening when Cronkite & Co. had been convinced Gerald Ford would run for vice president.

The other three books are useful in entirely different ways. Ronald Reagan: His Life and Rise to the Presidency (to be published later this month) is just what it declares itself to be. It is an excellent biography by a fine Los Angeles Times reporter, Bill Boyarsky, who has covered Reagan's political career since the beginning. Boyarsky tells us what to expect: Reagan will pursue the goals to which he has so often tells us committed himself (and so far he certainly has), goals that thrill his admirers and alarm those who are not. Boyarsky's Reagan is a gifted instinctive politician who will not hesitate, if necessary, to compromise and use moderate language to gain his far-rightist views. But given a honeymoon period intensified by the outpouring of sympathy and admiration, Reagan may not have to do much compromising.

It is beginning to look as if we will get a Reagan program little modified by Congress. Although I share the view of many, that the president's policies, domestic and foreign, will be deeply harmful to the nation and will cause suffering to the poor in great numbers, it may be best that Reagan's policies, substantially intact, receive a fair test. That way the nation will know whether to continue them or repudiate them. That way Reagan will not be able to blame someone else if (when?) things go terribly wrong.

Reagan the Man, the President is a series of essays by five respected correspondents of The New York Times. One of them, Richard Burt, has since joined the Department of Defense, no surprise, for he was widely regarded, even at The Times, as sharing the Pentagon's world view. No doubt the Timesmen, Burt excepted, will be dismissed by Reagan supporters as liberals, for they are clearly not convinced that the nation's problems will be solved by the simplistic nostrums in Reagan's old-fashioned pharmacopeia. Fair as they obviously are, they, like Boyarsky, fear that Reagan's small-town, boosterish view of the world is inadequate to the enormous task he has so confidently assumed.

The Future Under President Reagan is, in some ways, the most interesting. A group of Reagan intellectuals gives sophisticated arguments on behalf of simplistic pro-business, anti-Communist policies. These are obviously intelligent men with genuins concern for the nation, but they represent a white, middle-class comfortable America with little understanding of the misery, hunger and frustration that motivates hundreds of millions the world over, including the United States. Social Darwinists, they see the suffering not as humans like themselves, but as abstractions responsible for their own fate.

Who, after the events of that Monday afternoon, could fail to admire President Reagan's physical resilience, his light-hearted "grace under pressure." He is obviously a decent, well-intentioned man but his actions in office thus far and these books, whether admiring or objective, have reinforced my conviction that he has brought, to the enormously complex late 20th century, the naively optimistic mind set of a 19th-century entrepreneur. Policies based on nostalgia cannot work. Unless President Reagan can make his programs respond to present-day realities, he will fail. His failure is, of course, ours, but few of us are as insulated from economic hard times as he and the comfortable friends whose values he shares.

Finally, since these books look to the future, perhaps it might not be too presumptuous for this reviewer too make a prediction: the president will succeed in getting most of his pro-business program, the stock market will climb and so will his popularity until, somewhere along the way, it becomes obvious that Reagan, too, has failed. Then, as with poor Jimmy Carter, it will be downhill all the way. What happens after that? Well, it would be nice to think that the Democrats would then come forward with an effective program, but is there anyone, even among the Democrats, who really thinks they will?