SANTIAGO, CHILE, OCT. 2 -- Photographs tell the tale: one shows a stern, ramrod-straight Army general who took power in a bloody coup and presided over a brutal period of repression. The other shows a silver-haired grandfather with a salesman's smile and a twinkle in his eye.

The image of Gen. Augusto Pinochet has evolved over his 15 years of authoritarian rule. President Pinochet has changed from a soldier ensconced in the strict but secure regimen of military life into a politician of sorts, whose shrewd instincts but still unpolished skills are now being put to their most crucial test.

The way Chileans will vote Wednesday, to accept or reject Pinochet's bid for another eight years in the presidency, will depend at least in part on whether they see in him the general or the grandfather.

Today, thousands of his supporters drove through the streets of Santiago in boisterous caravans, honking their horns and shouting "Viva Pinochet!" Many of their cars were plastered with posters of a grinning, relaxed Pinochet -- hardly resembling the man who angrily warned Chileans on television last night that to vote against him would be to "allow Marxist sectors to take power."

People who know him say both images are part of the full portrait of the man. "He is neither an angel nor a devil," said Maria Eugenia Oyarzun, who has served in diplomatic and governmental posts under Pinochet.

Friends and associates describe a man who is a soldier first, last and always, fascinated with history and obsessed with his war -- a very personal war, one he feels destined to lead -- against communism. They describe a man who values loyalty above all, a man who, according to published reports, recently said of a former ally who now opposes him in the coming vote: "Better that he were dead."

Pinochet, 72, has ruled longer than any head of state in Chile's history. He has drawn the opprobrium of human rights groups and democratic governments worldwide for curtailing human rights and abusing the power of the state to persecute his opponents.

But acquaintances also tell of a man generous in repaying the loyalty he demands, playful at times in dealing with his aides, and hurt and confused by the fact that so many democratic-minded Chileans oppose him.

"Now they attack me," he said in an interview several years ago, before he ended almost all contact with the foreign press. "But later, sometime in the future, I am going to be remembered as the man who fought against communism and did well for his country."

Friends say he has no love of politics. Yet it was he who decided to stand as the government's sole candidate in the plebiscite. Although the heads of the armed forces formally made the decision, Pinochet's was the only vote that really counted. And it is he who now travels up and down the country giving speeches and kissing babies.

One thing on which those who know him agree is that before Sept. 11, 1973, when a military coup overthrew Salvador Allende and Pinochet took power, no one imagined he would ever approach the station he occupies today.

"Never," said William Thayer, who has known Pinochet for 50 years, when asked if he foresaw such prominence for the man he knew in the Army in 1938 as Lt. Augusto Pinochet Ugarte.

Thayer and Pinochet developed a bond because they had attended sister schools, Pinochet in the port city of Valparaiso and Thayer in the adjacent, more affluent, resort town of Vina del Mar. Thayer currently heads a publishing house with connections to the government and is an important figure in the National Renovation, a rightist party that supports Pinochet in the plebiscite.

Thayer recalls an incident from their military days in which Pinochet's recruits gathered around and made fun of him. Reprisals might have been expected, Thayer said, but none came -- illustrating, according to Thayer, that Pinochet does not harbor grudges or seek revenge.

Yet consider these off-the-cuff remarks, as quoted in the newsweekly Hoy, about an unnamed critic: "And twice I helped keep him from being put in prison. Here and now I wash my hands. . . . Now let's see if they put him in prison."

Pinochet was born Nov. 25, 1915, in Valparaiso, son of a customs official. His father wanted him to study medicine, but he entered the military academy instead, after twice being rejected because he was too young or physically weak.

The Army became his life. He earned a university degree and became a teacher at the Army war college, specializing in geopolitics. Friends say he is well read, particularly in history and political science, and he avidly reads communist literature -- to know his enemy.

Pinochet has portrayed himself as taking a leading role in planning the 1973 military coup. But it was Allende who named him head of the Army, barely a month before the coup, and Pinochet remained at least outwardly loyal until the end. Thayer declared that other officers were much more involved in the plotting than Pinochet. When Cuban leader Fidel Castro visited Allende in 1973, Pinochet was assigned as his local aide-de-camp.

Pinochet, as head of the preeminent Army, quickly overshadowed the other members of the junta, and evolved a highly personalized rule. Acquaintances say he sees as a personal mission ridding Chile of the "communist, totalitarian" forces that he insists had threatened to take power under Allende.

"We are at war!" Pinochet often says. The price Chile has paid for his war against the left is measured in lives, liberties, and the rupture of Chile's democratic traditions.

Hundreds were killed or are still listed as missing in the aftermath of the coup. A constant state of siege or emergency, lifted just weeks ago in anticipation of the plebiscite, kept Chileans from gathering in protest. The press was tightly controlled, and scores of journalists were jailed. Some kinds of criticism of the armed forces are still proscribed. The Communist Party is technically forbidden by law.

What Chileans got in return was relatively consistent economic policy and creation of a strong export sector. The telephones and the subways work, and the roads are well paved.

The general, by all accounts, rises early, retires early, drinks little, does not smoke. He is said to work out with weights and to be in excellent physical condition. Thayer describes him as an ascetic, although an opposition magazine has written of what it alleged were corrupt real estate deals through which Pinochet acquired an expensive private retreat. He and his wife Lucia have bought several other properties for themselves and some of their five children.

Pinochet in mufti has a trademark vanity, a large pearl tie tack, right below the knot. He is said to be devoted to his wife, who takes no official role in the government but has helped him politically with her work on behalf of social causes. She contributes to what polls show as Pinochet's disproportionate popularity among women.

His free-market economic policies and clampdown on political expression both figured in his biggest crisis, in 1983, when the economy collapsed and one out of six Chilean workers was out of a job. There were mass protests, as political tension that had built up over the years threatened to explode.

Pinochet came up with an unexpected response -- he loosened his grip on expression and let thousands of exiles return. After the crisis subsided a year later, he declared another state of siege.

In September 1986, Pinochet survived an assassination attempt when he was ambushed along a mountain road near Santiago. That incident, too, contributes to the legend -- official reports have him diving to the floor of his limousine to shelter his grandson from the would-be assassins' bullets.

But the plebiscite is a new kind of test. Opposition polls show the government would be enjoying more support with almost anyone else as its candidate. The old soldier presides over rallies, reminding supporters of the communist menace in a voice too squeaky for such an imposing personage, raising his hands in wooden gestures that seem practiced, but not practiced enough.

Polls show he is in trouble. But his opponents are haunted by the knowledge that he has been there before and somehow has managed to survive.