RONALD REAGAN, son of a shoe saleman from Tampico, Ill., is now the president-elect of the United States. That's pretty good for a guy who would have settled for being the play-by-play man for the Chicago Cubs. Today, Reagan has everyone on his side. But what kind of a president will he be?

Every four years, men issue self-serving statements aimed at convincing the public they are qualified to be president. The truth is there is no way to become qualified to be president. The truth is there is no way to become qualified to be president except by holding the job, and as Jimmy Carter can now attest, the price for gaining this experience may be political defeat.

We have had only three outstanding presidents in the less than 200 years we have held elections: George Washington, who gave the office an identity somewhere between that of king and prime minister; Abraham Lincoln, who, in order to save the Union, took unto the office powers that it didn't have and were forbidden to it by the Constitution; and Franklin Roosevelt, who molded the presidency into an effective tool for coping with America's international responsibilities. There were four other men who fought the office to a little better than a tie (Andrew Jackson, Theodore Roosevelt, Woodrow Wilson and Harry Truman), but because they lacked wisdom or sought refuge in arrogance, or failed to maintain their touch with the people, or served during a time when change was more difficult, they failed to realize its full potential. All the other 30 men who have held office were engulfed by it.

Ronald Reagan now becomes the oldest of the 38 men who have held this unique position. Whether he becomes one of the few successes or joins the many failures depends frist on whether he posesses the qualities that the seven shared and the 30 lacked. I, Self-knowledge

Since the primary prerequisite for handling the presidency is to ignore the immensity of it, a president must find the confidence to do so in self-knowledge. In a strange way, a man must have already survived some experience that tested his self-doubt in order to achieve the inner strength necessary to cope with the presidency.

Harry Truman was a failure for the first 50 years of his life; it never bothered him that he might fail as president. He'd already failed; he wasn't afraid of it.

Franklin Roosevelt lost the use of his legs to a child's disease. This patrician, this snob, crawled on his belly until he could hoist himself up on braces. The presidency never had a chance of beating him, he dominated it. He had it licked every time he got up on his feet.

Abraham Lincoln never had a proper education. Every time a ray of happiness seemed ready to shine on him, he'd lose an election, fall into debt, or someone chose to him would die.

The politicians laughed at him. But by his essential patience and devotion, by the very manner of his life and even his death, there was no greater human being than Lincoln; this country bumpkin who had known such misery bent the presidency to his own persuasion. We don't really remember President Lincoln; we remember Lincoln. Lincoln knew who he was. The presidency wasn't big enough for him.

Reagan knows himself better than most presidents, and he has kept his identity separate from politics. He doesn't really enjoy talking about politics. He'd rather talk about Hollywood or the Screen Actors Guild. He's proud of having been an actor, and the very fact that he may always be more proud of this accomplishment gives him a fighting chance to be a good president.

People who have been close to Reagan know that in private conversation he constantly harks back to his life in the movie industry and as a union official and a politician of the Hollywood years. It is his real identity, the self he has neither lost nor abandoned and from which he truly speaks as a man. Reagan knows who he is, and therefore he possesses the first prerequisite for being a good president. 2. Empathy

Once the election is over a president must quickly realize that he owes his fidelity to all the people, most especially those who didn't vote fro him. Empathy allows a president to be trusted. It is the mechanism for achieving consensus. Leadership is a combination of convincing people that you know what their circumstances are and that you are a fair person. Empathy is a necessary ingredient of both requirements.

Most of our better presidents learned to empathize through suffering personal tragedy or failure. The man who has gained success too easily finds it difficult to lead. There is something about losing and coming back from it that burns character into a man's soul, breeds confidence without arrogance and makes a man believable when he talks about problems. You can tell if a president knows what he's talking about: He's got lines in his face, his voice is controlled, his words compassionate. Presidents alsways try to act as though they know what they're talking about. Only a few really do.

Reagan is a man for whom advancement in life has come easily. Good looks, charm and simply being friendly to people have taken him a long way. Although the public record is obviously not the last word, it seems that only two events in Reagan's life were the source of any anxiety: His father had a drinking problem and his first marriage, to Jane Wyman, ended in divorce.

But these were not things that Reagan felt responsible for. While they obviously took a tool on him personally, in the end he could throw them off and place the blame elsewhere; they had no lasting effect on him They were not akin to Truman's liftime of failure, Franklin Roosevelt's loss of the use of his legs, Jackson's muddled personal life or Teddy Roosevelt's conquering of physical weakness and the death of his young bride.

Finding the requisite empathy with the millions of people for whom life has not flowed so well will be a major problem for Reagan. In a way, the good life for which Reagan often expresses his gratitude in private and the good fortune that has catapulted him to the pinnacle of politics are now his greatest enemies in office. Unfortunately, the only way to gain empathy is to suffer true adversity. If this must be done in office, then the possibilities are good that we all will suffer. 3. Strength in decision-making

The good presidents we have had have known what they wanted to do and then, by the force of their will, made it happen. The office demands decisions, and not to make them is a worse offense than being wrong. The presidency is what the people look to for example in finding the will to make difficult decisions in their own lives. When the president seems immobile, the country is.

To a large degree, Reagan sounds as if he knows where he is going. Often the perception of action is even more valuable than the fact, so he starts out in decent shape. But this decision-making function deserves close examination.

If you're an actor, you get up in the middle of the night to go to work. Your place of business is a set designed to look real. You get into a costume, people bring you coffee, you're made up. A crew in charge of cameras, lighting, scripts and other details moves about. You don't question what they're doing. Someone explains today's scene. You perform. Then you do the same thing over and over again until the director is satisfied. Critics ultimately review the picture. You become used to receiving the credit or taking the blame for a product that was not wholly yours.

Presidents are writers, directors, producers and actors rolled into one. They're the whole show. They take advice, but only at their own risk. It's their own neck, nobody else's. Just as an actor can't blame a poor performance on poor direction, a president can't blame his foreign policy on the secretary of state. There's no way to hide.

Reagan is comfortable with the essential responsibility of the presidency. He is prepared by the discipline of his former profession to let the critics judge his performance. But can he adjust to a situation where there are no retakes, where others will be looking to him to describe the scene? And can he also play the role that is not demanded of him?

I have been asked many times how Reagan goes about making a decision. The answer is that his decisions rarely originate with him. He is an endorser. It is fair to say that on some occasions he is presented with options and selects one, but it is also true that in other instances he simply looks to someone to tell him what to do.

It is this endorsing process that accounts for the difference between Reagan's tough-sounding campaign stances and his more moderate record as governor of California. The stump speeches are Reagan the performer playing to a known audience and sending the crowd away with its money's worth. As governor, there was no crowd, merely decisions to be made, only a few of which were exciting. Reagan sat with his California cabinet more as an equal than as its leader. Once consensus was arrived at or conflict resolved, he emerged as the spokesman, as the performer.

It didn't bother him that many decisions reached during his governorship were in severe conflict with is campaign oratory. While he was running for governor, one of his pledges was to hold the line on state taxes; one of his first acts as governor was to raise taxes. Reagan sees no conflict in this; it simply had to be done. His advisers had no option that would allow the pledge to be kept.

I would point out that there are indeed limits to the advice that Reagan will accept. Had his director in "Bedtime for Bonzo" demanded that he play a pivotl scene in the nude, he would have refused. If nuclear war were suggestd as one option to President Reagan, he'd pick something short of it. If his advisers are adequate, there is nothing to fear from President Reagan.

But he can be guided, and presidents who are too easily guided run the risk of losing the confidence of the people. This was one of President Carter's problems: People didn't think he was in charge.

Indeed, this is the difference between being governor of California and being president. It's not just that the job is bigger; it's that you must dominate it. You don't come to terms with the presidency; you grab it by the neck and you never let go.

This is not to say that Reagan's decision-making process won't work. Major contributions from his advisers won't necessarily deprive his administration of the possibility of having a direction, of being decisive and of providing the country with leadership. Reagan's essential value has always been as the "out-front" person willing to take the credit or the blame for what hs been a combined effort.

Reagan possesses other qualities that will help him be a good president. He is a delegator. All of our presidents since Kennedy have tried to hold the power of the office close to them, thus wasting most of it. Reagan receives information best in conversation with his advisers and doesn't encourage the mindless transfer of knowledge by sterile memorandums. Paper cannot talk back, cannot be questioned and cannot truly reflect the contours of any human problem.

A Reagan administration can go a long way toward restoring the confidence of those who look to us to maintain order in the world, simply because Reagan is perceived as a stronger man than Carter. During the campaign, Reagan developed a personal relationship with Henry Kissinger, and even if Kissinger is not included in the first wave of Reagan administration appointees, I would expect that his advice will be sought often. On the domestic front, the country is ready for some original approaches to the economy, the energy problem, job creation and urban deterioration. For some time, the people have been willing to move away from totally federal solutions to complex domestic problems. The Reagan election is more of a message to change domestic policy than a signal to alter our foreign relations.

Don't expect President Reagan to embark on any foreign trips in the first year of his administration. Ronald Reagan, being a delegator and believing that good administration calls for relying on advisers, will not rush to exercise personal diplomacy. He has never had great exposure in world politics, never enjoyed the perspective of foreigners, and knows that he must first acquire some familiarity with the foreign policy field before putting his personal stamp on this country's foreign relations.

Most of the upper-level appointees to the new administration will be drawn from the ranks of experienced participants in the Ford and Nixon years. Such men as George Shultz, Alexander Haig, John Connally, William Simon, Caspar Weinberger, Alan Greenspan and Arthur Burns can be expected to be included in a Reagan presidency. The Republican establishment may not be as creative as some critics would like, but after the chaotic Carter years, the people should feel reassured that the government is functioning and problems are being addressed in an orderly fashion. One of Carter's biggest mistakes was in not calling more upon as the perception grew that he really didn't have qualified people to lend credibility to his decisions.

Soon, Ronald Reagan will lose touch with what he has known of the people, he will hear mainly good news and even his friends will be reluctant to criticize him. Then he will have only his knowledge of himself to fall back on and his instincts in choosing his advisers. Soon he will grasp the size of the job he has won and wonder why he ever spent the past 12 yers of his life seeking it. He will look out from the rowboat and see no land, only the emptiness of the sea, and realize he has only himself to rely on. Then we will find out whether he can row the boat, and we can measure him against the other 38 men who have tried. We all must hope that he responds. He may not notice, but we're all in the boat with him.