LATE IN World War II, as the American army pushed into northern Italy, a young soldier named Bernard M. W. Knox was taking shelter in a bombed-out house when he spotted a gilt-edged book lying under the bricks and broken glass.

In the dust he saw a title in Latin. He picked the book up. It was a text of Virgil. Knox, who happened to be English, a Cambridge man, stared in delight at this little note of sanity, this reminder that the other, familiar, normal world still existed somewhere. He tried to get the book into his pocket but it wouldn't fit. His unit was moving up. Reluctantly, he threw the book down.

"If I ever get out of this," he vowed to himself, "I'm going back to the classics and study them seriously."

He did just that.

Hidden in a grove of oaks on a ridge at the edge of Rock Creek Park is a modest cul-de-sac guarded by two white brick posts. Eight small white houses line the curving road, at the end of which stands a trim one-story building with a pair of Greek columns at its entrance. Out-of-state cars wait in the driveways. Down the hill sprawls the slightly larger "Director's Residence" with picture windows overlooking the woods.

This is the Center for Hellenic Studies. Set up in 1961 with a $5 million grant from Paul Mellon's Old Dominion Foundation and run by Harvard University, it is home every year for eight junior scholars from around the world who live in the houses with their families, write, read, listen to visiting specialists in ancient Greece and have lunch together five days a week.

The land and the idea came from Marie Beale, wife of Truxton Beale, who in the late years of her life had been a friend of the great classicist Edith Hamilton and who wanted the center "to rediscover the humanism of the Hellenic Greeks."

"In those days there weren't many fellowships for junior people," said former soldier Knox, who at 68 has directed the center since it opened 20 years ago today. "People who haven't had time to write that book yet. Most of them spend their first four or five months reading, catching up with the field."

The eight, usually half of them Americans, study Greek history, philosophy or literature, "with a few Latinists, because after all, the Romans ran Greece for hundreds of years." Sometimes Knox brings in visitors to conduct seminars, and afterward the discussions run on for hours in the common room. A superb library, very little of it in English, covers two floors, and its collection of periodicals would shock anyone who thought ancient Greece was dead and buried.

Bernard Knox himself is walking proof that the classics are very much with us still, relevant even this far down the line of history. The Yorkshire native fought with the International Brigade in the Spanish Civil War until badly wounded ("It was my good luck; if it hadn't been so bad they would have sent me back to fight again"). Emigrating to America to marry an American woman he had met at Cambridge, he taught Latin at a prep school here, and after Pearl Harbor entered the U.S. Army as a private.

"I tried to enlist before that, but they wouldn't take noncitizens, so I wrote Henry L. Stimson, the secretary of war, and he wrote me a nice letter saying, 'You will surely hear from your draft board . . .' "

Drafted with a bunch of New Jersey Irishmen ("Christ, a Limey!" they shouted), he soon became thoroughly Americanized. Then followed officers' school, a shift to the Air Force, special operations with the Office of Strategic Services, a parachute drop into Occupied France to work with the maquis after the invasion. Knox was decorated by three countries and emerged a captain.

He has degrees from Cambridge, Yale, Harvard, Princeton and George Washington, and his list of honors ranges from a Guggenheim to the George Jean Nathan award for dramatic criticism. He has written and acted in a TV film on "Oedipus the King." Author of several works on Greek tragedy, he also has lectured on Thucydides to more than one fascinated group of American military experts.

In fact, his talks inspired the Naval War College to start teaching Thucydides and the Peloponnesian War, still a required course. (Gen. George Marshall once said no one could understand World War II who hadn't read about the Peloponnesian War.)

For Bernard Knox, ancient Greece is as fresh and immediate as the middle of next week.

"The Athenian democracy worked well," he said, "but it was restrictive. Women fared rather badly, and there was nothing for the slaves. Still, it was advanced for its time."

As everyone knows (or used to, anyway), the Greek city-states were so cut off from each other by the mountainous terrain that they developed independently, each with its own character.

"It was different from the Middle East, where you had those river economies, huge flat areas dominated by a river like the Nile or the Tigris-Euphrates requiring a bureaucracy run from the top (because of the need to coordinate vast numbers of workers for flood control and irrigation).

"But that still doesn't explain the tremendous outburst of creativity in Greece, in every field," he added.

A dramatic example is the standing male statue, which for 4,000 years the Egyptian sculptors had portrayed by a standard formula, frontally, the arms at the sides, the left leg advanced.

"Suddenly, the statues were freed. You see it in any chronological presentation of Greek sculptures: They move, they become natural and graceful--look at the figures on the Parthenon frieze."

Knox talked about it when he was given the Cosmos Club Award in 1979. Citing the fact that Sophocles' "Antigone" was adapted to the 1940s by both Anouilh and Brecht, that Simone Weil saw the modern world in the "Iliad," Knox asked:

"What is it about these plays and the work of Greek historians, poets and philosophers, that makes them so perpetually modern, defiant, like the heroes of the tragic genre they invented, of time and change? . . . The originality, brilliance and permanence of the Greek achievement is often, in fact, described as beyond explanation, as 'the Greek miracle.'

"But two components of that miracle can be identified as sources of the energy which has fueled Western civilization's movement ever since; they are, briefly stated, an assumption that man is the most important thing in the universe and a passion--and genius--for innovation."

Now, we may take innovation for granted in this era of new-model cars and the constant parade of "New! Improved!" laundry soaps, toothpastes and soft drinks. But the great Near Eastern civilizations, Knox said, "were, in fact, deliberately and skillfully engineered so as to maintain social stability, to perpetuate religious, political and artistic patterns . . . The Greeks had a respect for tradition, but it was not blind. And from first to last they were fascinated by novelty."

The demand for the new means competition, and competition was as much a part of the life of ancient Greece as it is here today: the Olympic games, the drama contests, the political elections, even the pottery, which in a few generations evolved technically--like the sculpture--far beyond the relatively static forms of other cultures.

The Athenians, according to their rivals, the Corinthians, "are innovators . . . bold beyond their strength . . . live a life of constant hard work and danger . . . their idea of a holiday is to do what has to be done . . . You could sum them up by saying that they were born never to live in peace and quiet themselves and to prevent the rest of the world from doing so."

Sounds familiar.

In his lecture, Knox points to the Renaissance as a massive revival of the revolutionary spirit of Greece--"and it is no accident that one of the most important elements in the European Renaissance was the rediscovery of Greek literature which, preserved in the Greek Byzantine empire, had been unknown to the Latin West all through the Middle Ages."

He traces the pattern down to modern times, reminding us, for instance, of Freud's Oedipus Complex, the radical ideas of Nietzsche (a Greek professor) and the work of John Dalton, the father of current atomic theory, who was indirectly influenced by 5th-century Greek philosophers.

As for man as "the measure of all things": According to the Greeks humankind was created, not by the gods, but along with them, parallel to them, springing from the same source. Hence their anthropocentric view of the universe.

"The tenuous and for the most part nonexistent connection between gods and ethical standards made the Greeks a nation of moral theorists," Knox said, "working out their own codes of law and conduct in a purely secular context; in the light of this constant effort it is easy to understand how they could invent history, philosophy, tragedy, ethnology, political science--to mention only a few of their contributions to the Western intellectual armory. It is no wonder either that in the 5th century exalted ideas of man's limitless potential as master of his environment came to the surface."

So it would seem that the study of ancient Greece is no mere arcane investigation of a lost world, but the study of our own roots, "so that, in fact, to be a professor of ancient Greek is to be a professor of modernity." There are insights for us all hidden in those dusty texts, and perhaps we should wonder, not why legions of fans turned out recently to hear I.F. Stone lecture at Georgetown on Socrates, but why it doesn't happen more often.