When kings were chosen, they were anointed by the people. They thus received the title Messiah, which means "the anointed one." In a religious sense kings were looked upon as a go-between between God and his people. The king could therefore also be called the "Son of God" and the country could be called the "Kingdom of God."

　　But before long Israel began to lose its power and the kingdom wasdivided into a Northern kingdom (Israel) and a Southern kingdom (Judea). In 722 B.C. the Northern kingdom was conquered by the Assyrians and it lost all political and religious significance. The Southern kingdom fared no better, being conquered by the Babylonians in 586 B.C. Its temple was destroyed and most of its people were carried off to slavery in Babylon. This "Babylonian captivity" lasted until 539 B.C. when the people were permitted to return to Jerusalem, and the great temple was restored. But for the rest of the period before the birth of Christ the Jews continued to live under foreign domination.

　　The question Jews constantly asked themselves was why the Kingdom of David was destroyed and why catastrophe after catastrophe rained down on them, for God had promised to hold Israel in his hand. But the people had also promised to keep God's commandments. It gradually became widely accepted that God was punishing Israel for her disobedience.

　　From around 750 B.C. various prophets began to come forward preaching God's wrath over Israel for not keeping his commandments. One day God would hold a Day of Judgment over Israel, they said. We call prophecies like these Doomsday prophecies.

　　In the course of time there came other prophets who preached that God would redeem a chosen few of his people and send them a "Prince of Peace" or a king of the House of David. He would restore the old Kingdom of David and the people would have a future of prosperity.

　　"The people that walked in darkness will see a great light," said the prophet Isaiah, and "they that dwell in the land of the shadow of death, upon them hath the light shined." We call prophecies like these prophecies of redemption.

　　To sum up: The children of Israel lived happily under King David. But later on when their situation deteriorated, their prophets began to proclaim that there would one day come a new king of the House of David. This "Messiah," or "Son of God," would "redeem" the people, restore Israel to greatness, and found a "Kingdom of God."

　　Jesus

　　I assume you are still with me, Sophie? The key words are "Messiah," "Son of God," and "Kingdom of God." At first it was all taken politically. In the time of Jesus, there were a lot of people who imagined that there would come a new "Messiah" in the sense of a political, military, and religious leader of the caliber of King David. This "savior" was thus looked upon as a national deliverer who would put an end to the suffering of the Jews under Roman domination.

　　Well and good. But there were also many people who were more farsighted. For the past two hundred years there had been prophets who believed that the promised "Messiah" would be the savior of the whole world. He would not simply free the Israelites from a foreign yoke, he would save all mankind from sin and blame——and not least, from death. The longing for "salvation" in the sense of redemption was widespread all over the Hellenistic world.

　　So along comes Jesus of Nazareth. He was not the only man ever to have come forward as the promised "Messiah." Jesus also uses the words "Son of God," the "Kingdom of God," and "redemption." In doing this he maintains the link with the old prophets. He rides into Jerusalem and allows himself to be acclaimed by the crowds as the savior of the people, thus playing directly on the way the old kings were installed in a characteristic "throne accession ritual." He also allows himself to be anointed by the people. "The time is fulfilled," he says, and "the Kingdom of God is at hand."

　　But here is a very important point: Jesus distinguished himself from the other "messiahs" by stating clearly that he was not a military or political rebel. His mission was much greater. He preached salvation and God's forgiveness for everyone. To the people he met on his way he said "Your sins are forgiven you for his name's sake."

　　Handing out the "remission of sins" in this way was totally unheard of. And what was even worse, he addressed God as "Father" (Abba). This was absolutely un-precedented in the Jewish community at that time. Itas therefore not long before there arose a wave of protest against him among the scribes.

　　So here was the situation: a great many people at the time of Jesus were waiting for a Messiah who would reestablish the Kingdom of God with a great flourish of trumpets (in other words, with fire and sword). The expression "Kingdom of God" was indeed a recurring theme in the preachings of Jesus——but in a much broader sense. Jesus said that the "Kingdom of God" is loving thy neighbor, compassion for the weak and the poor, and forgiveness of those who have erred.

　　This was a dramatic shift in the meaning of an age-old expression with warlike overtones. People were expecting a military leader who would soon proclaim the establishment of the Kingdom of God, and along comes Jesus in kirtle and sandals telling them that the Kingdom of God—— or the "new covenant"——is that you must "love thy neighbor as thyself." But that was not all, Sophie, he also said that we must love our enemies. When they strike us, we must not retaliate; we must even turn the other cheek. And we must forgive——not seven times but seventy times seven.

　　Jesus himself demonstrated that he was not above talking to harlots, corrupt usurers, and the politically subversive. But he went even further: he said that a good-for-nothing who has squandered all his father's inheritance—— or a humble publican who has pocketed official funds—— is righteous before God when he repents and prays for forgiveness, so great is God's mercy.

　　But hang on——he went a step further: Jesus said that such sinners were more righteous in the eyes of God and more deserving of God's forgiveness than the spotless Pharisees who went around flaunting their virtue.

　　Jesus pointed out that nobody can earn God's mercy. We cannot redeem ourselves (as many of the Greeks believed). The severe ethical demands made by Jesus in the Sermon on the Mount were not only to teach what the will of God meant, but also to show that no man is righteous in the eyes of God. God's mercy is boundless, but we have to turn to God and pray for his forgiveness.

　　I shall leave a more thorough study of Jesus and his teachings to your religion teacher. He will have quite a task. I hope he will succeed in showing what an excep-tional man Jesus was. In an ingenious way he used the language of his time to give the old war cries a totally new and broader content. It's not surprising that he ended on the Cross. His radical tidings of redemption were at odds with so many interests and power factors that he had to be removed.

　　When we talked about Socrates, we saw how dangerous it could be to appeal to people's reason. With Jesus we see how dangerous it can be to demand unconditional brotherly love and unconditional forgiveness. Even in the world of today we can see how mighty powers can come apart at the seams when confronted with simple demands for peace, love, food for the poor, and amnesty for the enemies of the state.

　　You may recall how incensed Plato was that the most righteous man in Athens had to forfeit his life. According to Christian teachings, Jesus was the only righteous person who ever lived. Nevertheless he was condemned to death. Christians say he died for the sake of humanity. This is what Christians usually call the "Passion" of Christ Jesus was the "suffering servant" who bore the sins of humanity in order that we could be "atoned" and saved from God's wrath.

　　Paul

　　A few days after Jesus had been crucified and buried, rumors spread that he had risen from the grave. He thereby proved that he was no ordinary man. He truly was the "Son of God."

　　We could say that the Christian Church was founded on Easter Morning with the rumors of the resurrection of Jesus. This is already established by Paul: "And if Christ be not risen, then is our preaching vain and your faith is also vain."

　　Now all mankind could hope for the resurrection of the body, for it was to save us that Jesus was crucified. But, dear Sophie, remember that from a Jewish point of view there was no question of the "immortality of the soul" or any form of "tranmigration"; that was a Greek——and therefore an Indo-European——thought. According to Christianity there is nothing in man——no "soul," for example—— that is in itself immortal. Although the Christian Church believes in the "resurrection of the body and eternal life," it is by God's miracle that we are saved from death and "damnation." It is neither through our own merit nor through any natural——or innate——ability.

　　So the early Christians began to preach the "glad tidings" of salvation through faith in Jesus Christ. Through his mediation, the "Kingdom of God" was about to be-come a reality. Now the entire world could be won for Christ. (The word "christ" is a Greek translation of the Hebrew word "messiah," the anointed one.)

　　A few years after the death of Jesus, the Pharisee Paul converted to Christianity. Through his many missionary journeys across the whole of the Greco-Roman world he made Christianity a worldwide religion. We hear of this in the Acts of the Apostles. Paul's preaching and guidance for the Christians is known to us from the many epistles written by him to the early Christian congregations.

　　He then turns up in Athens. He wanders straight into the city square of the philosophic capital. And it is said that "his spirit was stirred in him, when he saw the city wholly given to idolatry." He visited the Jewish synagogue in Athens and conversed with Epicurean and Stoic philosophers. They took him up to the Areopagos hill and asked him: "May we know what this new doctrine, whereof thou speakest, is? For thou bringest certain strange things to our ears: we would know therefore what these things mean."

　　Can you imagine it, Sophie? A Jew suddenly appears in the Athenian marketplace and starts talking about a savior who was hung on a cross and later rose from the grave. Even from this visit of Paul in Athens we sense a coming collision between Greek philosophy and the doctrine of Christian redemption. But Paul clearly succeeds in getting the Athenians to listen to him. From the Areopa-gos——and beneath the proud temples of the Acropolis—— he makes the following speech:

　　"Ye men of Athens, I perceive that in all things ye are too superstitious. For as I passed by, and beheld your devotions, I found an altar with this inscription, TO THE UNKNOWN GOD. Whom therefore ye ignorantly worship, him declare I unto you.

　　God that made the world and all things therein, seeing that he is Lord of heaven and earth, dwelleth not in temples made with hands; neither is worshipped with men's hands, as though he needed any thing, seeing he giveth to all life, and breath, and all things. And hath made of one blood all nations of men for to dwell on all the face of the earth, and hath determined the times before appointed, and the bounds of their habitation; that they should seek the Lord, if haply they might feel after him and find him, though he be not far from every one of us. For in him we live, and move, and have our being; as certain also of your own poets have said, For we are also his offspring. Forasmuch then as we are the offspring of God, we ought not to think that the Godhead is like unto gold, or silver, or stone, graven by art and man's device. And the times of this ignorance God winked at; but now commandeth all men everywhere to repent:

　　Because he hath appointed a day, in the which he will judge the world in righteousness by that man whom he hath ordained; whereof he hath given as-surance unto all men, in that he hath raised him from the dead."

　　Paul in Athens, Sophie! Christianity has begun to penetrate the Greco-Roman world as something else, something completely different from Epicurean, Stoic, or Neoplatonic philosophy. But Paul nevertheless finds some common ground in this culture. He emphasizes that the search for God is natural to all men. This was not new to the Greeks. But what was new in Paul's preaching is that God has also revealed himself to mankind and has in truth reached out to them. So he is no longer a "philosophic God" that people can approach with their understanding. Neither is he "an image of goldr silver or stone"——there were plenty of those both on the Acropolis and down in the marketplace! He is a God that "dwelleth not in temples made with hands." He is a personal God who intervenes in the course of history and dies on the Cross for the sake of mankind.

　　When Paul had made his speech on the Areopagos, we read in the Acts of the Apostles, some mocked him for what he said about the resurrection from the dead. But others said: "We will hear thee again of this matter." There were also some who followed Paul and began to believe in Christianity. One of them, it is worth noting, was a woman named Damaris. Women were amongst the most fervent converts to Christianity.

　　So Paul continued his missionary activities. A few decades after the death of Jesus, Christian congregations were already established in all the important Greek and Roman cities——in Athens, in Rome, in Alexandria, in Ephesos, and in Corinth. In the space of three to four hundred years, the entire Hellenistic world had become Christian.

　　The Creed

　　It was not only as a missionary that Paul came to have a fundamental significance for Christianity. He also had great influence within the Christian congregations. There was a widespread need for spiritual guidance.

　　One important question in the early years after Jesus was whether non-Jews could become Christians without first becoming Jews. Should a Greek, for instance, observe the dietary laws? Paul believed it to be unnecessary. Christianity was more than a Jewish sect. It addressed itself to everybody in a universal message of salvation. The "Old Covenant" between God and Israel had been replaced by the "New Covenant" which Jesus had established between God and mankind.

　　However, Christianity was not the only religion at that time. We have seen how Hellenism was influenced by a fusion of religions. It was thus vitally necessary for the church to step forward with a concise summary of the Christian doctrine, both in order to distance itself from other religions and to prevent schisms within the Christian Church. Therefore the first Creed was established, summing up the central Christian "dogmas" or tenets.

　　One such central tenet was that Jesus was both God and man. He was not the "Son of God" on the strength of his actions alone. He was God himself. But he was also a "true man" who had shared the misfortunes of mankind and actually suffered on the Cross.

　　This may sound like a contradiction. But the message of the church was precisely that God became man. Jesus was not a "demigod" (which was half man, half god). Belief in such "demigods" was quite widespread in Greek and Hellenistic religions. The church taught that Jesus was "perfect God, perfect man."

　　Postscript

　　Let me try to say a few words about how all this hangs together, my dear Sophie. As Christianity makes its entry into the Greco-Roman world we are witnessing a dramatic meeting of two cultures. We are also seeing one of history's great cultural revolutions.

　　We are about to step out of antiquity. Almost one thousand years have passed since the days of the early Greek philosophers. Ahead of us we have the Christian Middle Ages, which also lasted for about a thousand years.

　　The German poet Goethe once said that "he who cannot draw on three thousand years is living from hand to mouth." I don't want you to end up in such a sad state. I will do what I can to acquaint you with your historical roots. It is the only way to become a human being. It is the only way to become more than a naked ape. It is the only way to avoid floating in a vacuum.

　　"It is the only way to become a human being. It is the only way to become more than a naked ape ……"

　　Sophie sat for a while staring into the garden through the little holes in the hedge. She was beginning to understand why it was so important to know about her historical roots. It had certainly been important to the Children of Israel.

　　She herself was just an ordinary person. But if she knew her historical roots, she would be a little less ordinary.

　　She would not be living on this planet for more than aew years. But if the history of mankind was her own history, in a way she was thousands of years old.

　　The Middle Ages…… going only part of the way is not the same as going the wrong way…

　　A week passed without Sophie hearing from Alberto Knox. There were no more postcards from Lebanon either, although she and Joanna still talked about the cards they found in the major's cabin. Joanna had had the fright of her life, but as nothing further seemed to hap-pen, the immediate terror faded and was submerged in homework and badminton.

　　Sophie read Alberto's letters over and over, looking for some clue that would throw light on the Hilde mystery. Doing so also gave her plenty of opportunity to digest the classical philosophy. She no longer had difficulty in distinguishing Democritus and Socrates, or Plato and Aristotle, from each other.

　　On Friday, May 25, she was in the kitchen fixing dinner before her mother got home. It was their regular Friday agreement. Today she was making fish soup with fish balls and carrots. Plain and simple.

　　Outside it was becoming windy. As Sophie stood stirring the casserole she turned toward the window. The birch trees were waving like cornstalks.

　　Suddenly something smacked against the window-pane. Sophie turned around again and discovered a card sticking to the window.

　　It was a postcard. She could read it through the glass: "Hilde Moller Knag, c/o Sophie Amundsen."

　　She thought as much! She opened the window and took the card. It could hardly have blown all the way from Lebanon!

　　This card was also dated June 15. Sophie removed the casserole from the stove and sat down at the kitchen table. The card read:

　　Dear Hilde, I don't know whether it will still be your birthday when you read this card. I hope so, in a way; or at least that not too many days have gone by. A week or two for Sophie does not have to mean just as long for us. I shall be coming home for Midsummer Eve, so we can sit together for hours in the glider, looking out over the sea, Hilde. We have so much to talk about. Love from Dad, who sometimes gets very depressed about the thousand-year-long strife between Jews, Christians, and Muslims. I have to keep reminding myself that all three religions stem from Abraham. So I suppose they all pray to the same God. Down here, Cain and Abel have not finished killing each other.

　　P.S. Please say hello to Sophie. Poor child, she still doesn't know how this whole thing hangs together. But perhaps you do?

　　Sophie put her head down on the table, exhausted. One thing was certain——she had no idea how this thing hung together. But Hilde did, presumably.

　　If Hilde's father asked her to say hello to Sophie, it had to mean that Hilde knew more about Sophie than Sophie did about Hilde. It was all so complicated that Sophie went back to fixing dinner.

　　A postcard that smacked against the kitchen window all by itself! You could call that airmail!

　　As soon as she had set the casserole on the stove again, the telephone rang.

　　Suppose it was Dad! She wished desperately that he would come home so she could tell him everything that had happened in these last weeks. But it was probably only Joanna or Mom. Sophie snatched up the phone.

　　"Sophie Amundsen," she said.

　　"It's me," said a voice.

　　Sophie was sure of three things: it was not her father. But it was a man's voice, and a voice she knew she had heard before.

　　"Who is this?"

　　"It's Alberto."

　　"Ohhh!"

　　Sophie was at a loss for words. It was the voice from the Acropolis video that she had recognized.

　　"Are you all right?"

　　"Sure."

　　"From now on there will be no more letters."

　　"But I didn't send you a frog!"

　　"We must meet in person. It's beginning to be urgent, you see."

　　"Why?"

　　"Hilde's father is closing in on us."

　　"Closing in how?"

　　"On all sides, Sophie. We have to work together now."

　　"How……?"

　　"But you can't help much before I have told you about the Middle Ages. We ought to cover the Renaissance and the seventeenth century as well. Berkeley is a key figure……"

　　"Wasn't he the man in the picture at the major's cabin?"

　　"That very same. Maybe the atual struggle will be waged over his philosophy."

　　"You make it sound like a war."

　　"I would rather call it a battle of wills. We have to attract Hilde's attention and get her over on our side before her father comes home to Lillesand."

　　"I don't get it at all."

　　"Perhaps the philosophers can open your eyes. Meet me at St. Mary's Church at eight o'clock tomorrow morning. But come alone, my child."

　　"So early in the morning?"

　　The telephone clicked.

　　"Hello?"

　　He had hung up! Sophie rushed back to the stove just before the fish soup boiled over.

　　St. Mary's Church? That was an old stone church from the Middle Ages. It was only used for concerts and very special ceremonies. And in the summer it was sometimes open to tourists. But surely it wasn't open in the middle of the night?

　　When her mother got home, Sophie had put the card from Lebanon with everything else from Alberto and Hilde. After dinner she went over to Joanna's place.

　　"We have to make a very special arrangement," she said as soon as her friend opened the door.

　　She said no more until Joanna had closed her bedroom door.

　　"It's rather problematic," Sophie went on.

　　"Spit it out!"

　　"I'm going to have to tell Mom that I'm staying the night here."

　　"Great!"

　　"But it's only something I'm saying, you see. I've got to go somewhere else."

　　"That's bad. Is it a guy?"

　　"No, it's to do with Hilde."

　　Joanna whistled softly, and Sophie looked her severely in the eye.

　　"I'm coming over this evening," she said, "but at seven o'clock I've got to sneak out again. You've got to cover for me until I get back."

　　"But where are you going? What is it you have to do?"

　　"Sorry. My lips are sealed."

　　Sleepovers were never a problem. On the contrary, almost. Sometimes Sophie got the impression that her mother enjoyed having the house to herself.

　　"You'll be home for breakfast, I suppose?" was her mother's only remark as Sophie left the house.

　　"If I'm not, you know where I am."

　　What on earth made her say that? It was the one weak spot.

　　Sophie's visit began like any other sleepover, with talk until late into the night. The only difference was that when they finally settled down to sleep at about two o'clock, Sophie set the alarm clock to a quarter to seven.

　　Five hours later, Joanna woke briefly as Sophie switched off the buzzer.

　　"Take care," she mumbled.

　　Then Sophie was on her way. St. Mary's Church lay on the outskirts of the old part of town. It was several miles walk away, but even though she had only slept for a few hours she felt wide awake.

　　It was almost eight o'clock when she stood at the entrance to the old stone church. Sophie tried the massive door. It was unlocked!

　　Inside the church it was as deserted and silent as the church was old. A bluish light filtered in through the stained-glass windows revealing a myriad of tiny particles of dust hovering in the air. The dust seemed to gather in thick beams this way and that inside the church. Sophie sat on one of the benches in the center of the nave, staring toward the altar at an old crucifix painted with muted colors.

　　Some minutes passed. Suddenly the organ began to play. Sophie dared not look around. It sounded like an ancient hymn, probably from the Middle Ages.

　　There was silence again. Then she heard footsteps approaching from behind her. Should she look around? She chose instead to fix her eyes on the Cross.

　　The footsteps passed her on their way up the aisle and she saw a figure dressed in a brown monk's habit. Sophie could have sworn it was a monk right out of the Middle Ages.

　　She was nervous, but not scared out of her wits. In front of the altar the monk turned in a half-circle and then climbed up into the pulpit. He leaned over the edge, looked down at Sophie, and addressed her in Latin:

　　"Gloria Patri, et Filio, et Spiritui Sancto. Sicut erat in principio, et nunc, et semper et in saecula saeculorum. Amen."

　　"Talk sense, silly!" Sophie burst out.

　　Her voice resounded all around the old stone church.

　　Although she realized that the monk had to be Alberto Knox, she regretted her outburst in this venerable place f worship. But she had been nervous, and when you're nervous its comforting to break all taboos.

　　"Shhh!" Alberto held up one hand as priests do when they want the congregation to be seated. "Middle Ages began at four," he said. "Middle Ages began at four?" asked Sophie, feeling stupid but no longer nervous. "About four o'clock, yes. And then it was five and six and seven. But it was as if time stood still. And it got to be eight and nine and ten. But it was still the Middle Ages, you see. Time to get up to a new day, you may think. Yes, I see what you mean. But it is still Sunday, one long endless row of Sundays. And it got to be eleven and twelve and thirteen. This was the period we call the High Gothic, when the great cathedrals of Europe were built. And then, some time around fourteen hours, at two in the afternoon, a cock crowed——and the Middle Ages began to ebb away." "So the Middle Ages lasted for ten hours then," said Sophie. Alberto thrust his head forward out of the brown monk's cowl and surveyed his congregation, which consisted of a fourteen-year-old girl.

　　"If each hour was a hundred years, yes. We can pretend that Jesus was born at midnight. Paul began his missionary journeys just before half past one in the morning and died in Rome a quarter of an hour later. Around three in the morning the Christian church was more or less banned, but by A.D. 313 it was an accepted religion in the Roman Empire. That was in the reign of the Emperor Constantine. The holy emperor himself was first baptized on his deathbed many years later. From the year 380 Christianity was the official religion throughout the entire Roman Empire."

　　"Didn't the Roman Empire fall?" "It was just beginning to crumble. We are standing before one of the greatest changes in the history of culture. Rome in the fourth century was being threatened both by barbarians pressing in from the north and by disintegration from within. In A.D. 330 Constantine the Great moved the capital of the Empire from Rome to Constantinople, the city he had founded at the approach to the Black Sea. Many people considered the new city the "second Rome." In 395 the Roman Empire was divided in two——a Western Empire with Rome as its center, and an Eastern Empire with the new city of Constantinople as its capital. Rome was plundered by bar-barians in 410, and in 476 the whole of the Western Empire was destroyed. The Eastern Empire continued to exist as a state right up until 1453 when the Turks conquered Constantinople."

　　"And its name got changed to Istanbul?"

　　"That's right! Istanbul is its latest name. Another date we should notice is 529. That was the year when the church closed Plato's Academy in Athens. In the same year, the Benedictine order, the first of the great monastic orders, was founded. The year 529 thus became a symbol of the way the Christian Church put the lid on Greek philosophy. From then on, monasteries had the monopoly of education, reflection, and meditation. The clock was ticking toward half past five ……"

　　Sophie saw what Alberto meant by all these times. Midnight was 0, one o'clock was 100 years after Christ, six o'clock was 600 years after Christ, and 14 hours was 1,400 years after Christ……

　　Alberto continued: "The Middle Ages actually means the period between two other epochs. The expression arose during the Renaissance. The Dark Ages, as they were also called, were seen then as one interminable thousand-year-long night which had settled over Europe between antiquity and the Renaissance. The word 'medieval' is used negatively nowadays about anything that is over-authoritative and inflexible. But many historians now consider the Middle Ages to have been a thousand-year period of germination and growth. The school system, for instance, was developed in the Middle Ages. The first convent schools were opened quite early on in the period, and cathedral schools followed in the twelfth century. Around the year 1200 the first universities were founded, and the subjects to be studied were grouped into various 'faculties,' just as they are today."

　　"A thousnd years is a really long time."

　　"Yes, but Christianity took time to reach the masses. Moreover, in the course of the Middle Ages the various nation-states established themselves, with cities and citizens, folk music and folktales. What would fairy tales and folk songs have been without the Middle Ages? What would Europe have been, even? A Roman province, perhaps. Yet the resonance in such names as England, France, or Germany is the very same boundless deep we call the Middle Ages. There are many shining fish swimming around in those depths, although we do not always catch sight of them. Snorri lived in the Middle Ages. So did Saint Olaf and Charlemagne, to say nothing of Romeo and Juliet, Joan of Arc, Ivanhoe, the Pied Piper of Hamelin, and many mighty princes and majestic kings, chivalrous knights and fair damsels, anonymous stained-glass window makers and ingenious organ builders. And I haven't even mentioned friars, crusaders, or witches."

　　"You haven't mentioned the clergy, either."

　　"Correct. Christianity didn't come to Norway, by the way, until the eleventh century. It would be an exaggeration to say that the Nordic countries converted to Christianity at one fell swoop. Ancient heathen beliefs persisted under the surface of Christianity, and many of these pre-Christian elements became integrated with Christianity. In Scandinavian Christmas celebrations, for example, Christian and Old Norse customs are wedded even to this day. And here the old saying applies, that married folk grow to resemble each other. Yuletide cookies, Yuletide piglets, and Yuletide ale begin to resemble the Three Wise Men from the Orient and the manger in Bethlehem. But without doubt, Christianity gradually became the predominant philosophy of life. Therefore we usually speak of the Middle Ages as being a unifying force of Christian culture."

　　"So it wasn't all gloom, then?"

　　"The first centuries after the year 400 really were a cultural decline. The Roman period had been a high culture, with big cities that had sewers, public baths, and libraries, not to mention proud architecture. In the early centuries of the Middle Ages this entire culture crum-bled. So did its trade and economy. In the Middle Ages people returned to payment in kind and bartering. The economy was now characterized by feudalism, which meant that a few powerful nobles owned the land, which the serfs had to toil on in order to live. The population also declined steeply in the first centuries. Rome had over a million inhabitants in antiquity. But by 600, the population of the old Roman capital had fallen to 40,000, a mere fraction of what it had been. Thus a relatively small population was left to wander among what remained of the majestic edifices of the city's former glory. When they needed building materials, there were plenty of ruins to supply them. This is naturally a source of great sorrow to present-day archeologists, who would rather have seen medieval man leave the ancient monuments untouched."

　　"It's easy to know better after the fact."

　　"From a political point of view, the Roman period was already over by the end of the fourth century. However, the Bishop of Rome became the supreme head of the Roman Catholic Church. He was given the title 'Pope'——in Latin 'papa,' which means what it says—— and gradually became looked upon as Christ's deputy on earth. Rome was thus the Christian capital throughout most of the medieval period. But as the kings and bishops of the new nation-states became more and more powerful, some of them were bold enough to stand up to the might of the church."

　　"You said the church closed Plato's Academy in Athens. Does that mean that all the Greek philosophers were forgotten?"

　　"Not entirely. Some of the writings of Aristotle and Plato were known. But the old Roman Empire was gradually divided into three different cultures. In Western Europe we had a Latinized Christian culture with Rome as its capital. In Eastern Europe we had a Greek Christian culture with Constantinople as its capital. This city began to be called by its Greek name, Byzantiu. We therefore speak of the Byzantine Middle Ages as opposed to the Roman Catholic Middle Ages. However, North Africa and the Middle East had also been part of the Roman Empire. This area developed during the Middle Ages into an Arabic-speaking Muslim culture. After the death of Muhammad in 632, both the Middle East and North Africa were won over to Islam. Shortly thereafter, Spain also became part of the world of Islamic culture. Islam adopted Mecca, Medina, Jerusalem, and Bagdad as holy cities. From the point of view of cultural history, it is interesting to note that the Arabs also took over the ancient Hellenistic city of Alexandria. Thus much of the old Greek science was inherited by the Arabs. All through the Middle Ages, the Arabs were predominant hi sciences such as mathematics, chemistry, astronomy, and medicine. Nowadays we still use Arabic figures. In a number of areas Arabic culture was superior to Christian culture."

　　"I wanted to know what happened to Greek philosophy."

　　"Can you imagine a broad river that divides for a while into three different streams before it once again becomes one great wide river?"

　　"Yes."

　　"Then you can also see how the Greco-Roman culture was divided, but survived through the three cultures: the Roman Catholic in the west, the Byzantine in the east, and the Arabic in the south. Although it's greatly oversimplified, we could say that Neoplatonism was handed down in the west, Plato in the east, and Aristotle to the Arabs in the south. But there was also something of them all in all three streams. The point is that at the end of the Middle Ages, all three streams came together in Northern Italy. The Arabic influence came from the Arabs in Spain, the Greek influence from Greece and the Byzantine Empire. And now we see the beginning of the Renaissance, the 'rebirth' of antique culture. In one sense, antique culture had survived the Dark Ages."

　　"I see."

　　"But let us not anticipate the course of events. We mast first talk a little about medieval philosophy. I shall not speak from this pulpit any more. I'm coming down."

　　Sophie's eyes were heavy from too little sleep. When she saw the strange monk descending from the pulpit of St. Mary's Church, she felt as if she were dreaming.

　　Alberto walked toward the altar rail. He looked up at the altar with its ancient crucifix, then he walked slowly toward Sophie. He sat down beside her on the bench of the pew.

　　It was a strange feeling, being so close to him. Under his cowl Sophie saw a pair of deep brown eyes. They belonged to a middle-aged man with dark hair and a little pointed beard. Who are you, she wondered. Why have you turned my life upside down?

　　"We shall become better acquainted by and by," he said, as if he had read her thoughts.

　　As they sat there together, with the light that filtered into the church through the stained-glass windows becoming sharper and sharper, Alberto Knox began to talk about medieval philosophy.

　　"The medieval philosophers took it almost for granted that Christianity was true," he began. "The question was whether we must simply believe the Christian revelation or whether we can approach the Christian truths with the help of reason. What was the relationship between the Greek philosophers and what the Bible said? Was there a contradiction between the Bible and reason, or were belief and knowledge compatible? Almost all medieval philosophy centered on this one question."

　　Sophie nodded impatiently. She had been through this in her religion class.

　　"We shall see how the two most prominent medieval philosophers dealt with this question, and we might as well begin with St. Augustine, who lived from 354 to 430. In this one person's life we can observe the actual transition from late antiquity to the Early Middle Ages. Augustine was born in the little town of Tagaste in North Africa. At the age of sixteen he went to Carthage to study. Later he traveled to Rome and Milan, and lived the last years of his life in the town of Hippo, a few miles west of Carthage. However, he was not a Christian all his life. Augustine examned several different religions and philosophies before he became a Christian."

　　"Could you give some examples?"

　　"For a time he was a Manichaean. The Manichaeans were a religious sect that was extremely characteristic of late antiquity. Their doctrine was half religion and half philosophy, asserting that the world consisted of a dualism of good and evil, light and darkness, spirit and matter. With his spirit, mankind could rise above the world of matter and thus prepare for the salvation of his soul. But this sharp division between good and evil gave the young Augustine no peace of mind. He was completely preoccupied with what we like to call the 'problem of evil.' By this we mean the question of where evil comes from. For a time he was influenced by Stoic philosophy, and according to the Stoics, there was no sharp division between good and evil. However, his principal leanings were toward the other significant philosophy of late antiquity, Neoplatonism. Here he came across the idea that all existence is divine in nature."

　　"So he became a Neoplatonic bishop?"

　　"Yes, you could say that. He became a Christian first, but the Christianity of St. Augustine is largely influenced by Platonic ideas. And therefore, Sophie, therefore you have to understand that there is no dramatic break with Greek philosophy the minute we enter the Christian Middle Ages. Much of Greek philosophy was carried over to the new age through Fathers of the Church like St. Augustine."

　　"Do you mean that St. Augustine was half Christian and half Neoplatonist?"

　　"He himself believed he was a hundred-percent Christian although he saw no real contradiction between Christianity and the philosophy of Plato. For him, the similarity between Plato and the Christian doctrine was so apparent that he thought Plato must have had knowl-edge of the Old Testament. This, of course, is highly improbable. Let us rather say that it was St. Augustine who 'christianized' Plato."

　　"So he didn't turn his back on everything that had to do with philosophy when he started believing in Christianity?"

　　"No, but he pointed out that there are limits to how far reason can get you in religious questions. Christianity is a divine mystery that we can only perceive through faith. But if we believe in Christianity, God will 'illuminate' the soul so that we experience a sort of supernatural knowledge of God. St. Augustine had felt within himself that there was a limit to how far philosophy could go. Not before he became a Christian did he find peace in his own soul. 'Our heart is not quiet until it rests in Thee,' he writes."

　　"I don't quite understand how Plato's ideas could go together with Christianity," Sophie objected. "What about the eternal ideas?"

　　"Well, St. Augustine certainly maintains that God created the world out of the void, and that was a Biblical idea. The Greeks preferred the idea that the world had always existed. But St. Augustine believed that before God created the world, the 'ideas' were in the Divine mind. So he located the Platonic ideas in God and in that way preserved the Platonic view of eternal ideas."

　　"That was smart."

　　"But it indicates how not only St. Augustine but many of the other Church Fathers bent over backward to bring Greek and Jewish thought together. In a sense they were of two cultures. Augustine also inclined to Neoplatonism in his view of evil. He believed, like Plotinus, that evil is the 'absence of God.' Evil has no independent existence, it is something that is not, for God's creation is in fact only good. Evil comes from mankind's disobedience, Augustine believed. Or, in his own words, 'The good will is God's work; the evil will is the falling away from God's work.' "

　　"Did he also believe that man has a divine soul?"

　　"Yes and no. St. Augustine maintained that there is an insurmountable barrier between God and the world. In this he stands firmly on Biblical ground, rejecting the doctrine of Plotinus that everything is one. But he nevertheless emphasizes that man is a spiritual being. He has a material body——which belongs to the physical wrld which 'moth and rust doth corrupt'——but he also has a soul which can know God."

　　"What happens to the soul when we die?"

　　"According to St. Augustine, the entire human race was lost after the Fall of Man. But God nevertheless decided that certain people should be saved from perdition."

　　"In that case, God could just as well have decided that everybody should be saved."

　　"As far as that goes, St. Augustine denied that man has any right to criticize God, referring to Paul's Epistle to the Romans: 'O Man, who art thou that replies! against God? Shall the thing formed say to him that formed it; why hast thou made me thus? or Hath not the potter power over the clay, of the same lump to make one vessel unto honor and another unto dishonor?' "

　　"So God sits up in his Heaven playing with people? And as soon as he is dissatisfied with one of his creations, he just throws it away."

　　"St. Augustine's point was that no man deserves God's redemption. And yet God has chosen some to be saved from damnation, so for him there was nothing secret about who will be saved and who damned. It is preordained. We are entirely at his mercy."

　　"So in a way, he returned to the old belief in fate."

　　"Perhaps. But St. Augustine did not renounce man's responsibility for his own life. He taught that we must live in awareness of being among the chosen. He did not deny that we have free will. But God has 'foreseen' how we will live."

　　"Isn't that rather unfair?" asked Sophie. "Socrates said that we all had the same chances because we all had the same common sense. But St. Augustine divides people into two groups. One group gets saved and the other gets damned."

　　"You are right in that St. Augustine's theology is considerably removed from the humanism of Athens. But St. Augustine wasn't dividing humanity into two groups. He was merely expounding the Biblical doctrine of salvation and damnation. He explained this in a learned work called the City of God."

　　"Tell me about that."

　　"The expression 'City of God,' or 'Kingdom of God,' comes from the Bible and the teachings of Jesus. St. Augustine believed that all human history is a struggle between the 'Kingdom of God' and the 'Kingdom of the World.' The two 'kingdoms' are not political kingdoms distinct from each other. They struggle for mastery inside every single person. Nevertheless, the Kingdom of God is more or less clearly present in the Church, and the Kingdom of the World is present in the State——for example, in the Roman Empire, which was in decline at the time of St. Augustine. This conception became increasingly clear as Church and State fought for supremacy throughout the Middle Ages. There is no salvation outside the Church,' it was now said. St. Augustine's 'City of God' eventually became identical with the es-tablished Church. Not until the Reformation in the sixteenth century was there any protest against the idea that people could only obtain salvation through the Church."

　　"It was about time!"

　　"We can also observe that St. Augustine was the first philosopher we have come across to draw history into his philosophy. The struggle between good and evil was by no means new. What was new was that for Augustine the struggle was played out in history. There is not much of Plato in this aspect of St. Augustine's work. He was more influenced by the linear view of history as we meet it in the Old Testament: the idea that God needs all of history in order to realize his Kingdom of God. History is necessary for the enlightenment of man and the de-struction of evil. Or, as St. Augustine put it, 'Divine foresight directs the history of mankind from Adam to the end of time as if it were the story of one man who gradually develops from childhood to old age.' "

　　Sophie looked at her watch. "It's ten o'clock," she said. "I'll have to go soon."

　　"But first I must tell you about the other great medieval philosopher. Shall we sit outside?"

　　Alberto stood up. He placed the palms of his hands together and began to stride down the aisle. He looked as if he was praying or meditating deeply on some spiritual truh. Sophie followed him; she felt she had no choice.

　　The sun had not yet broken through the morning clouds. Alberto seated himself on a bench outside the church. Sophie wondered what people would think if anyone came by. Sitting on a church bench at ten in the morning was odd in itself, and sitting with a medieval monk wouldn't make things look any better.

　　"It is eight o'clock," he began. "About four hundred years have elapsed since St. Augustine, and now school starts. From now until ten o'clock, convent schools will have the monopoly on education. Between ten and eleven o'clock the first cathedral schools will be founded, followed at noon by the first universities. The great Gothic cathedrals will be built at the same time. This church, too, dates from the 1200s——or what we call the High Gothic period. In this town they couldn't afford a large cathedral."

　　"They didn't need one," Sophie said. "I hate empty churches."

　　"Ah, but the great cathedrals were not built only for large congregations. They were built to the glory of God and were in themselves a kind of religious celebration. However, something else happened during this period which has special significance for philosophers like us."

　　Alberto continued: "The influence of the Arabs of Spain began to make itself felt. Throughout the Middle Ages, the Arabs had kept the Aristotelian tradition alive, and from the end of the twelfth century, Arab scholars began to arrive in Northern Italy at the invitation of the nobles. Many of Aristotle's writings thus became known and were translated from Greek and Arabic into Latin. This created a new interest in the natural sciences and infused new life into the question of the Christian revelation's relationship to Greek philosophy. Aristotle could obviously no longer be ignored in matters of science, but when should one attend to Aristotle the phi-losopher, and when should one stick to the Bible? Do you see?"

　　Sophie nodded, and the monk went on:

　　"The greatest and most significant philosopher of this period was St. Thomas Aquinas, who lived from 1225 to 1274. He came from the little town of Aquino, between Rome and Naples, but he also worked as a teacher at the University of Paris. I call him a philosopher but he was just as much a theologian. There was no great difference between philosophy and theology at that time. Briefly, we can say that Aquinas christianized Aristotle in the same way that St. Augustine christianized Plato in early medieval times."

　　"Wasn't it rather an odd thing to do, christianizing philosophers who had lived several hundred years before Christ?"

　　"You could say so. But by 'christianizing' these two great Greek philosophers, we only mean that they were interpreted and explained in such a way that they were no longer considered a threat to Christian dogma. Aquinas was among those who tried to make Aristotle's philosophy compatible with Christianity. We say that he created the great synthesis between faith and knowledge. He did this by entering the philosophy of Aristotle and taking him at his word."

　　"I'm sorry, but I had hardly any sleep last night. I'm afraid you'll have to explain it more clearly."

　　"Aquinas believed that there need be no conflict between what philosophy or reason teaches us and what the Christian Revelation or faith teaches us. Christendom and philosophy often say the same thing. So we can frequently reason ourselves to the same truths that we can read in the Bible."

　　"How come? Can reason tell us that God created the world in six days or that Jesus was the Son of God?"

　　"No, those so-called verities of faith are only accessible through belief and the Christian Revelation. But Aquinas believed in the existence of a number of 'natural theological truths.' By that he meant truths that could be reached both through Christian faith and through our innate or natural reason. For example, the truth that there is a God. Aquinas believed that there are two paths to God. One path goes through faith and the Christian Revelation, and the other goes through reason and the senses. Of these two, te path of faith and revelation is certainly the surest, because it is easy to lose one's way by trusting to reason alone. But Aquinas's point was that there need not be any conflict between a philosopher like Aristotle and the Christian doctrine."

　　"So we can take our choice between believing Aristotle and believing the Bible?"

　　"Not at all. Aristotle goes only part of the way because he didn't know of the Christian revelation. But going only part of the way is not the same as going the wrong way. For example, it is not wrong to say that Athens is in Europe. But neither is it particularly precise. If a book only tells you that Athens is a city in Europe, it would be wise to look it up in a geography book as well. There you would find the whole truth that Athens is the capital of Greece, a small country in southeastern Europe. If you are lucky you might be told a little about the Acropolis as well. Not to mention Socrates, Plato, and Aristotle."

　　"But the first bit of information about Athens was true."

　　"Exactly! Aquinas wanted to prove that there is only one truth. So when Aristotle shows us something our reason tells us is true, it is not in conflict with Christian teaching. We can arrive successfully at one aspect of the truth with the aid of reason and the evidence of our senses. For example, the kind of truths Aristotle refers to when he describes the plant and the animal kingdom. Another aspect of the truth is revealed to us by God through the Bible. But the two aspects of the truth overlap at significant points. There are many questions about which the Bible and reason tell us exactly the same thing."

　　"Like there being a God?"

　　"Exactly. Aristotle's philosophy also presumed the existence of a God——or a formal cause——which sets all natural processes going. But he gives no further description of God. For this we must rely solely on the Bible and the teachings of Jesus."

　　"Is it so absolutely certain that there is a God?"

　　"It can be disputed, obviously. But even in our day most people will agree that human reason is certainly not capable of disproving the existence of God. Aquinas went further. He believed that he could prove God's existence on the basis of Aristotle's philosophy."

　　"Not bad!"

　　"With our reason we can recognize that everything around us must have a 'formal cause,' he believed. God has revealed himself to mankind both through the Bible and through reason. There is thus both a 'theology of faith' and a 'natural theology.' The same is true of the moral aspect. The Bible teaches us how God wants us to live. But God has also given us a conscience which enables us to distinguish between right and wrong on a 'natural' basis. There are thus also 'two paths' to a moral life. We know that it is wrong to harm people even if we haven't read in the Bible that we must 'do unto others as you would have them do unto you.' Here, too, the surest guide is to follow the Bible's commandment."

　　"I think I understand," said Sophie now. "It's almost like how we know there's a thunderstorm, by seeing the lightning and by hearing the thunder."

　　"That's right! We can hear the thunder even if we are blind, and we can see the lightning even if we are deaf. It's best if we can both see and hear, of course. But there is no contradiction between what we see and what we hear. On the contrary——the two impressions reinforce each other."

　　"I see."

　　"Let me add another picture. If you read a novel—— John Steinbeck's Of Mice and Men, for example ……"

　　"I've read that, actually."

　　"Don't you feel you know something about the author just by reading his book?"

　　"I realize there is a person who wrote it."

　　"Is that all you know about him?"

　　"He seems to care about outsiders."

　　"When you read this book——which is Steinbeck's creation——you get to know something about Steinbeck's nature as well. But you cannot expect to get any personal information about the author. Could you tell from reading Of Mice and Men how old the author was when he wrote it, where he lived, or how many children he had?"

　　"Of course not."

　　"But you can find this informtion in a biography of John Steinbeck. Only in a biography——or an autobiography——can you get better acquainted with Steinbeck, the person."

　　"That's true."

　　"That's more or less how it is with God's Creation and the Bible. We can recognize that there is a God just by walking around in the natural world. We can easily see that He loves flowers and animals, otherwise He would not have made them. But information about God, the person, is only found in the Bible——or in God's 'autobiography,' if you like."

　　"You're good at finding examples."

　　"Mmmm……"

　　For the first time Alberto just sat there thinking—— without answering.

　　"Does all this have anything to do with Hilde?" Sophie could not help asking.

　　"We don't know whether there is a 'Hilde' at all."

　　"But we know someone is planting evidence of her all over the place. Postcards, a silk scarf, a green wallet, a stocking ……"

　　Alberto nodded. "And it seems as if it is Hilde's father who is deciding how many clues he will plant," he said. "For now, all we know is that someone is sending us a lot of postcards. I wish he would write something about himself too. But we shall return to that later."

　　"It's a quarter to eleven. I'll have to get home before the end of the Middle Ages."

　　"I shall just conclude with a few words about how Aquinas adopted Aristotle's philosophy in all the areas where it did not collide with the Church's theology. These included his logic, his theory of knowledge, and not least his natural philosophy. Do you recall, for ex-ample, how Aristotle described the progressive scale of life from plants and animals to humans?"

　　Sophie nodded.

　　"Aristotle believed that this scale indicated a God that constituted a sort of maximum of existence. This scheme of things was not difficult to align with Christian theology. According to Aquinas, there was a progressive degree of existence from plants and animals to man, from man to angels, and from angels to God. Man, like animals, has a body and sensory organs, but man also has intelligence which enables him to reason things out.

　　Angels have no such body with sensory organs, which is why they have spontaneous and immediate intelligence. They have no need to 'ponder,' like humans; they have no need to reason out conclusions. They know everything that man can know without having to learn it step by step like us. And since angels have no body, they can never die. They are not everlasting like God, because they were once created by God. But they have no body that they must one day depart from, and so they will never die."

　　"That sounds lovely!"

　　"But up above the angels, God rules, Sophie. He can see and know everything in one single coherent vision."

　　"So he can see us now."

　　"Yes, perhaps he can. But not 'now.' For God, time does not exist as it does for us. Our 'now' is not God's 'now.' Because many weeks pass for us, they do not necessarily pass for God."

　　"That's creepy!" Sophie exclaimed. She put her hand over her mouth. Alberto looked down at her, and Sophie continued: "I got another card from Hilde's father yesterday. He wrote something like——even if it takes a week or two for Sophie, that doesn't have to mean it will be that long for us. That's almost the same as what you said about God!"

　　Sophie could see a sudden frown flash across Alberto's face beneath the brown cowl.

　　"He ought to be ashamed of himself!"

　　Sophie didn't quite understand what Alberto meant. He went on: "Unfortunately, Aquinas also adopted Aristotle's view of women. You may perhaps recall that Aristotle thought a woman was more or less an incomplete man. He also thought that children only inherit the father's characteristics, since a woman was passive and receptive while the man was active and creative. According to Aquinas, these views harmonized with the message of the Bible——which, for example, tells us that woman was made out of Adam's rib."

　　"Nonsense!"

　　"It's interesting to note that the eggs of mammals were not discovered until 1827. It was therefore perhaps not so surprising that people thought it was the man who was the creative and liegiving force in reproduction. We can moreover note that, according to Aquinas, it is only as nature-being that woman is inferior to man. Woman's soul is equal to man's soul. In Heaven there is complete equality of the sexes because all physical gender differences cease to exist."

　　"That's cold comfort. Weren't there any women philosophers in the Middle Ages?"

　　"The life of the church in the Middle Ages was heavily dominated by men. But that did not mean that there were no women thinkers. One of them was Hildegard of Bingen……"

　　Sophie's eyes widened:

　　"Does she have anything to do with Hilde?"

　　"What a question! Hildegard lived as a nun in the Rhine Valley from 1098 to 1179. In spite of being a woman, she worked as preacher, author, physician, botanist, and naturalist. She is an example of the fact that women were often more practical, more scientific even, in the Middle Ages."

　　"But what about Hilde?"

　　"It was an ancient Christian and Jewish belief that God was not only a man. He also had a female side, or 'mother nature.' Women, too, are created in God's likeness. In Greek, this female side of God is called Sophia. 'Sophia' or 'Sophie' means wisdom."

　　Sophie shook her head resignedly. Why had nobody ever told her that? And why had she never asked?

　　Alberto continued: "Sophia, or God's mother nature, had a certain significance both for Jews and in the Greek Orthodox Church throughout the Middle Ages. In the west she was forgotten. But along comes Hildegard. Sophia appeared to her in a vision, dressed in a golden tunic adorned with costly jewels ……"

　　Sophie stood up. Sophia had revealed herself to Hildegard in a vision ……

　　"Maybe I will appear to Hilde."

　　She sat down again. For the third time Alberto laid his hand on her shoulder.

　　"That is something we must look into. But now it is past eleven o'clock. You must go home, and we are approaching a new era. I shall summon you to a meeting on the Renaissance. Hermes will come get you in the garden."

　　With that the strange monk rose and began to walk toward the church. Sophie stayed where she was, thinking about Hildegard and Sophia, Hilde and Sophie. Suddenly she jumped up and ran after the monk-robed philosopher, calling:

　　"Was there also an Alberto in the Middle Ages?"

　　Alberto slowed his pace somewhat, turned his head slightly and said, "Aquinas had a famous philosophy teacher called Albert the Great……"

　　With that he bowed his head and disappeared through the door of St. Mary's Church.

　　Sophie was not satisfied with his answer. She followed him into the church. But now it was completely empty. Did he go through the floor?

　　Just as she was leaving the church she noticed a picture of the Madonna. She went up to it and studied it closely. Suddenly she discovered a little drop of water under one of the Madonna's eyes. Was it a tear?

　　Sophie rushed out of the church and hurried back to Joanna's.

　　The Renaissance

　　…O divine lineage in mortal guise…

　　It was just twelve when Sophie reached Joanna's front gate, out of breath with running. Joanna was standing in the front yard outside her family's yellow house.

　　"You've been gone for five hours!" Joanna said sharply.

　　Sophie shook her head.

　　"No, I've been gone for more than a thousand years."

　　"Where on earth have you been? You're crazy. Your mom called half an hour ago."

　　"What did you tell her?"

　　"I said you were at the drugstore. She said would you call her when you got back. But you should have seen my mom and dad when they came in with hot chocolate and rolls at ten this morning …… and your bed was empty."

　　"What did you say to them?"

　　"It was really embarrassing. I told them you went home because we got mad at each other."

　　"So we'd better hurry up and be friends again. And we have to make sure your parents don't talk to my mom for a few days. Do you think we can do that?"

　　Joanna shrugged. Just then her father came around the corner with a wheelbarrow. He had a pair of coveralls on and was busy clearing up last year's leaves and twigs.

　　"Aha——so you're friends again, I see. Well, there's not so much as a single lea left on the basement steps now."

　　"Fine," said Sophie. "So perhaps we can have our hot chocolate there instead of in bed."

　　Joanna's dad gave a forced laugh, but Joanna gasped. Verbal exchanges had always been more robust in Sophie's family than at the more well-to-do home of Mr. Ingebrigtsen, the financial adviser, and his wife.

　　"I'm sorry, Joanna, but I felt I ought to take part in this cover-up operation as well."

　　"Are you going to tell me about it?"

　　"Sure, if you walk home with me. Because it's not for the ears of financial advisers or overgrown Barbie dolls."

　　"That's a rotten thing to say! I suppose you think a rocky marriage that drives one of the partners away to sea is better?"

　　"Probably not. But I hardly slept last night. And another thing, I've begun to wonder whether Hilde can see everything we do."

　　They began to walk toward Clover Close.

　　"You mean she might have second sight?"

　　"Maybe. Maybe not."

　　Joanna was clearly not enthusiastic about all this secrecy.

　　"But that doesn't explain why her father sent a lot of crazy postcards to an empty cabin in the woods."

　　"I admit that is a weak spot."

　　"Do you want to tell me where you have been?"

　　So she did. Sophie told her everything, about the mysterious philosophy course as well. She made Joanna swear to keep everything secret.

　　They walked for a long time without speaking. As they approached Clover Close, Joanna said, "I don't like it."

　　She stopped at Sophie's gate and turned to go home again.

　　"Nobody asked you to like it. But philosophy is not a harmless party game. It's about who we are and where we come from. Do you think we learn enough about that at school?"

　　"Nobody can answer questions like that anyway."

　　"Yes, but we don't even learn to ask them!"

　　Lunch was on the table when Sophie walked into the kitchen. Nothing was said about her not having called from Joanna's.

　　After lunch Sophie announced that she was going to take a nap. She admitted she had hardly slept at Joanna's house, which was not at all unusual at a sleepover.

　　Before getting into bed she stood in front of the big brass mirror which now hung on her wall. At first she only saw her own white and exhausted face. But then—— behind her own face, the faintest suggestion of another face seemed to appear. Sophie took one or two deep breaths. It was no good starting to imagine things.

　　She studied the sharp contours of her own pale face framed by that impossible hair which defied any style but nature's own. But beyond that face was the apparition of another girl. Suddenly the other girl began to wink frantically with both eyes, as if to signal that she was really in there on the other side. The apparition lasted only a few seconds. Then she was gone.

　　Sophie sat down on the edge of the bed. She had absolutely no doubt that it was Hilde she had seen in the mirror. She had caught a glimpse of her picture on a school I.D. in the major's cabin. It must have been the same girl she had seen in the mirror.

　　Wasn't it odd, how she always experienced mysterious things like this when she was dead tired. It meant that afterward she always had to ask herself whether it really had happened.

　　Sophie laid her clothes on the chair and crawled into bed. She fell asleep at once and had a strangely vivid dream.

　　She dreamed she was standing in a large garden that sloped down to a red boathouse. On the dock behind it sat a young fair-haired girl gazing out over the water. Sophie walked down and sat beside her. But the girl seemed not to notice her. Sophie introduced herself. "I'm Sophie," she said. But the other girl could apparently neither see nor hear her. Suddenly Sophie heard a voice calling, "Hilde!" At once the girl jumped up from where she was sitting and ran as fast as she could up to the house. She couldn't have been deaf or blind after all. A middle-aged man came striding from the house toward her. He was wearing a khaki uniform and a blue beret. The girl threw her arms around his neck and he swung her around a few times. Sophie noticed a little gold crucifix on a chain lying on the dock where th girl had been sitting. She picked it up and held it in her hand. Then she woke up.

　　Sophie looked at the clock. She had been asleep for two hours. She sat up in bed, thinking about the strange dream. It was so real that she felt as if she had actually lived the experience. She was equally sure that the house and the dock really existed somewhere. Surely it resembled the picture she had seen hanging in the major's cabin? Anyway, there was no doubt at all that the girl in her dream was Hilde Moller Knag and that the man was her father, home from Lebanon. In her dream he had looked a lot like Alberto Knox ……

　　As Sophie stood up and began to tidy her bed, she found a gold crucifix on a chain under her pillow. On the back of the crucifix there were three letters engraved: HMK.

　　This was not the first time Sophie had dreamed she found a treasure. But this was definitely the first time she had brought it back from the dream.

　　"Damn!" she said aloud.

　　She was so mad that she opened the closet door and hurled the delicate crucifix up onto the top shelf with the silk scarf, the white stocking, and the postcards from Lebanon.

　　The next morning Sophie woke up to a big breakfast of hot rolls, orange juice, eggs, and vegetable salad. It was not often that her mother was up before Sophie on a Sunday morning. When she was, she liked to fix a solid meal for Sophie.

　　While they were eating, Mom said, "There's a strange dog in the garden. It's been sniffing round the old hedge all morning. I can't imagine what it's doing here, can you?"

　　"Yes!" Sophie burst out, and at once regretted it.

　　"Has it been here before?"

　　Sophie had already left the table and gone into the living room to look out of the window facing the large garden. It was just as she thought.

　　Hermes was lying in front of the secret entrance to her den.

　　What should she say? She had no time to think of anything before her mother came and stood beside her.

　　"Did you say it had been here before?" she asked.

　　"I expect it buried a bone there and now it's come to fetch its treasure. Dogs have memories too ……"

　　"Maybe you're right, Sophie. You're the animal psychologist in the family."

　　Sophie thought feverishly.

　　"I'll take it home," she said.

　　"You know where it lives, then?"

　　Sophie shrugged her shoulders.

　　"It's probably got an address on its collar."

　　A couple of minutes later Sophie was on her way down the garden. When Hermes caught sight of her he came lolloping toward her, wagging his tail and jumping up to her.

　　"Good boy, Hermes!" said Sophie.

　　She knew her mother was watching from the window. She prayed he would not go through the hedge. But the dog dashed toward the gravel path in front of the house, streaked across the front yard, and jumped up to the gate.

　　When they had shut the gate behind them, Hermes continued to run a few yards in front of Sophie. It was a long way. Sophie and Hermes were not the only ones out for a Sunday walk. Whole families were setting off for the day. Sophie felt a pang of envy.

　　From time to time Hermes would run off and sniff at another dog or at something interesting by a garden hedge, but as soon as Sophie called "Here, boy!" he would come back to her at once.

　　They crossed an old pasture, a large playing field, and a playground, and emerged into an area with more traffic. They continued toward the town center along a broad street with cobbled stones and streetcars. Hermes led the way across the town square and up Church Street. They came out into the Old Town, with its massive staid town houses from the turn of the century. It was almost half past one.

　　Now they were on the other side of town. Sophie had not been there very often. Once when she was little, she remembered, she had been taken to visit an old aunt in one of these streets.

　　Eventually they reached a little square between several old houses. It was called New Square, although it all looked very old. But then the whole town was old; it had been founded way back in the Middle Ages.

　　Hermes walked toward No. 14, where he stood still and waited for Sophie to open the door.Her heart began to beat faster.

　　Inside the front door there were a number of green mailboxes attached to a panel. Sophie noticed a postcard hanging from one of the mailboxes in the top row. It had a stamped message from the mailman across it to the effect that the addressee was unknown.

　　The addressee was Hilde Moller Knag, 14 New Square. It was postmarked June 15. That was not for two weeks, but the mailman had obviously not noticed that.

　　Sophie took the card down and read it:

　　Dear Hilde, Now Sophie is coming to the philosopher's house. She will soon be fifteen, but you were fifteen yesterday. Or is it today, Hilde? If it is today, it must be late, then. But our watches do not always agree. One generation ages while another generation is brought forth. In the meantime history takes its course. Have you ever thought that the history of Europe is like a human life? Antiquity is like the childhood of Europe. Then come the interminable Middle Ages——Europe's schoolday. But at last comes the Renaissance; the long school-day is over. Europe comes of age in a burst of exuberance and a thirst for life. We could say that the Renaissance is Europe's fifteenth birthday! It is mid-June, my child, and it is wonderful to be alive!

　　P.S. Sorry to hear you lost your gold crucifix. You must learn to take better care of your things. Love, Dad——who is just around the corner.

　　Hermes was already on his way up the stairs. Sophie took the postcard with her and followed. She had to run to keep up with him; he was wagging his tail delightedly. They passed the second, third, and fourth stories. From then on there was only an attic staircase. Were they going up to the roof? Hermes clambered on up the stairs and stopped outside a narrow door, which he scratched at with his paw.

　　Sophie heard footsteps approaching from inside. The door opened, and there stood Alberto Knox. He had changed his clothes and was now wearing another costume. It consisted of white hose, red knee-breeches, and a yellow jacket with padded shoulders. He reminded Sophie of a joker in a deck of cards. If she was not much mistaken, this was a typical Renaissance costume.

　　"What a clown!" Sophie exclaimed, giving him a little push so that she could go inside the apartment.

　　Once again she had taken out her fear and shyness on the unfortunate philosophy teacher. Sophie's thoughts were in a turmoil because of the postcard she had found down in the hallway.

　　"Be calm, my child," said Alberto, closing the door behind her.

　　"And here's the mail," she said, handing him the postcard as if she held him responsible for it.

　　Alberto read it and shook his head.

　　"He gets more and more audacious. I wouldn't be surprised if he isn't using us as a kind of birthday diversion for his daughter."

　　With that he tore the postcard into small pieces and threw them into the wastepaper basket.

　　"It said that Hilde has lost her crucifix," said Sophie.

　　"So I read."

　　"And I found it, the same one, under my pillow at home. Can you understand how it got there?"

　　Alberto looked gravely into her eyes.

　　"It may seem alluring. But it's just a cheap trick that costs him no effort whatsoever. Let us rather concentrate on the big white rabbit that is pulled out of the universe's top hat."

　　They went into the living room. It was one of the most extraordinary rooms Sophie had ever seen.

　　Alberto lived in a spacious attic apartment with sloping walls. A sharp light directly from the sky flooded the room from a skylight set into one of the walls. There was also another window facing the town. Through this window Sophie could look over all the roofs in the Old Town.

　　But what amazed Sophie most was all the stuff the room was filled with——furniture and objects from various historical periods. There was a sofa from the thirties, an old desk from the beginning of the century, and a chair that had to be hundreds of years old. But it wasn't just the furniture. Old objects, either useful or decorative, were jumbled together on shelves and cupboards. There were old clocks and vases, mortars and retorts, knives and dolls,quill pens and bookends, octants and sextants, compasses and barometers. One entire wall was covered with books, but not the sort of books found in most bookstores. The book collection itself was a cross section of the production of many hundreds of years. On the other walls hung drawings and paintings, some from recent decades, but most of them also very old. There were a lot of old charts and maps on the walls too, and as far as Norway was concerned, they were not very accurate.

　　Sophie stood for several minutes without speaking and took everything in.

　　"What a lot of old junk you've collected," she said.

　　"Now then! Just think of how many centuries of history I have preserved in this room. I wouldn't exactly call it junk."

　　"Do you manage an antique shop or something?"

　　Alberto looked almost pained.

　　"We can't all let ourselves be washed away by the tide of history, Sophie. Some of us must tarry in order to gather up what has been left along the river banks."

　　"What an odd thing to say."

　　"Yes, but none the less true, child. We do not live in our own time alone; we carry our history within us. Don't forget that everything you see in this room was once brand new. That old sixteenth-century wooden doll might have been made for a five-year-old girl's birthday. By her old grandfather, maybe…… then she became a teenager, then an adult, and then she married. Maybe she had a daughter of her own and gave the doll to her. She grew old, and one day she died. Although she had lived for a very long time, one day she was dead and gone. And she will never return. Actually she was only here for a short visit. But her doll——well, there it is on the shelf."

　　"Everything sounds so sad and solemn when you talk like that."

　　"Life is both sad and solemn. We are let into a wonderful world, we meet one another here, greet each other——and wander together for a brief moment. Then we lose each other and disappear as suddenly and unreasonably as we arrived."

　　"May I ask you something?"

　　"We're not playing hide-and-seek any more."

　　"Why did you move into the major's cabin?"

　　"So that we would not be so far from each other, when we were only talking by letter. I knew the old cabin would be empty."

　　"So you just moved in?"

　　"That's right. I moved in."

　　"Then maybe you can also explain how Hilde's father knew you were there."

　　"If I am right, he knows practically everything."

　　"But I still can't understand at all how you get a mailman to deliver mail in the middle of the woods!"

　　Alberto smiled archly.

　　"Even things like that are a pure bagatelle for Hilde's father. Cheap hocus-pocus, simple sleight of hand. We are living under what is possibly the world's closest surveillance."

　　Sophie could feel herself getting angry.

　　"If I ever meet him, I'll scratch his eyes out!"

　　Alberto walked over and sat down on the sofa. Sophie followed and sank into a deep armchair.

　　"Only philosophy can bring us closer to Hilde's father," Alberto said at last. "Today I shall tell you about the Renaissance."

　　"Shoot."

　　"Not very long after St. Thomas Aquinas, cracks began to appear in the unifying culture of Christianity. Philosophy and science broke away more and more from the theology of the Church, thus enabling religious life to attain a freer relationship to reasoning. More people now emphasized that we cannot reach God through rationalism because God is in all ways unknowable. The important thing for a man was not to understand the divine mystery but to submit to God's will.

　　"As religion and science could now relate more freely to each other, the way was open both to new scientific methods and a new religious fervor. Thus the basis was created for two powerful upheavals in the fifteenth and sixteenth centuries, namely, the Renaissance and the Reformation."

　　"Can we take them one at a time?"

　　"By the Renaissance we mean the rich cultural development that began in the late fourteenth century. It started in Northern Italy and spread rapidly northward during the fifteenth and sixteenth centuries."

　　"Didn't you tell me that the word 'renaissance' meant rebirth?"

　　" did indeed, and that which was to be reborn was the art and culture of antiquity. We also speak of Renaissance humanism, since now, after the long Dark Ages in which every aspect of life was seen through divine light, everything once again revolved around man. 'Go to the source' was the motto, and that meant the humanism of antiquity first and foremost.

　　"It almost became a popular pastime to dig up ancient sculptures and scrolls, just as it became fashionable to learn Greek. The study of Greek humanism also had a pedagogical aim. Reading humanistic subjects provided a 'classical education' and developed what may be called human qualities. 'Horses are born,' it was said, 'but human beings are not born——they are formed.' "

　　"Do we have to be educated to be human beings?"

　　"Yes, that was the thought. But before we take a closer look at the ideas of Renaissance humanism, we must say a little about the political and cultural background of the Renaissance."

　　Alberto rose from the sofa and began to wander about the room. After a while he paused and pointed to an antique instrument on one of the shelves.

　　"What is that?" he asked.

　　"It looks like an old compass."

　　"Quite right."

　　He then pointed to an ancient firearm hanging on the wall above the sofa.

　　"And that?"

　　"An old-fashioned rifle."

　　"Exactly——and this?"

　　Alberto pulled a large book off one of the bookshelves.

　　"It's an old book."

　　"To be absolutely precise, it is an incunabulum."

　　"An incunabulum?"

　　"Actually, it means 'cradle.' The word is used about books printed in the cradle days of printing. That is, before 1500."

　　"Is it really that old?"

　　"That old, yes. And these three discoveries——the compass, firearms, and the printing press——were essential preconditions for this new period we call the Renaissance."

　　"You'll have to explain that a bit more clearly."

　　"The compass made it easier to navigate. In other words, it was the basis for the great voyages of discovery. So were firearms in a way. The new weapons gave the Europeans military superiority over American and Asiatic cultures, although firearms were also an important factor in Europe. Printing played an important part in spreading the Renaissance humanists' new ideas. And the art of printing was, not least, one of the factors that forced the Church to relinquish its former position as sole disseminator of knowledge. New inventions and instruments began to follow thick and fast. One important instrument, for example, was the telescope, which resulted in a completely new basis for astronomy." "And finally came rockets and space probes." "Now you're going too fast. But you could say that a process started in the Renaissance finally brought people to the moon. Or for that matter to Hiroshima and Chernobyl. However, it all began with changes on the cultural and economic front. An important condition was the transition from a subsistence economy to a monetary economy. Toward the end of the Middle Ages, cities had developed, with effective trades and a lively commerce of new goods, a monetary economy and banking. A middle class arose which developed a certain freedom with regard to the basic conditions of life. Necessities became something that could be bought for money. This state of affairs rewarded people's diligence, imagination, and ingenuity. New demands were made on the individual."

　　"It's a bit like the way Greek cities developed two thousand years earlier."

　　"Not altogether untrue. I told you how Greek philosophy broke away from the mythological world picture that was linked to peasant culture. In the same way, the Renaissance middle class began to break away from the feudal lords and the power of the church. As this was happening, Greek culture was being rediscovered through a closer contact with the Arabs in Spain and the Byzantine culture in the east."

　　"The three diverging streams from antiquity joined into one great river."

　　"You are an attentive pupil. That gives you some background on the Renaissance. I shall now tell you about the new ideas."

　　"Okay, but I'll have to go home and eat."

　　Alberto satdown on the sofa again. He looked at Sophie.

　　"Above all else, the Renaissance resulted in a new view of mankind. The humanism of the Renaissance brought a new belief in man and his worth, in striking contrast to the biased medieval emphasis on the sinful nature of man. Man was now considered infinitely great and valuable. One of the central figures of the Renaissance was Marsilio Ficino, who exclaimed: 'Know thyself, O divine lineage in mortal guise!' Another central figure, Pica della Mirandola, wrote the Oration on the Dignity of Man, something that would have been unthinkable in the Middle Ages.

　　"Throughout the whole medieval period, the point of departure had always been God. The humanists of the Renaissance took as their point of departure man himself."

　　"But so did the Greek philosophers."

　　"That is precisely why we speak of a 'rebirth' of antiquity's humanism. But Renaissance humanism was to an even greater extent characterized by individualism. We are not only human beings, we are unique individuals. This idea could then lead to an almost unrestrained worship of genius. The ideal became what we call the Renaissance man, a man of universal genius embracing all aspects of life, art, and science. The new view of man also manifested itself in an interest in the human anatomy. As in ancient times, people once again began to dissect the dead to discover how the body was constructed. It was imperative both for medical science and for art. Once again it became usual for works of art to depict the nude. High time, after a thousand years of prudery. Man was bold enough to be himself again. There was no longer anything to be ashamed of."

　　"It sounds intoxicating," said Sophie, leaning her arms on the little table that stood between her and the philosopher.

　　"Undeniably. The new view of mankind led to a whole new outlook. Man did not exist purely for God's sake. Man could therefore delight in life here and now. And with this new freedom to develop, the possibilities were limitless. The aim was now to exceed all boundaries. This was also a new idea, seen from the Greek humanistic point of view; the humanists of antiquity had emphasized the importance of tranquility, moderation, and restraint."

　　"And the Renaissance humanists lost their restraint?"

　　"They were certainly not especially moderate. They behaved as if the whole world had been reawakened.

　　They became intensely conscious of their epoch, which is what led them to introduce the term 'Middle Ages' to cover the centuries between antiquity and their own time. There was an unrivaled development in all spheres of life. Art and architecture, literature, music, philosophy, and science flourished as never before. I will mention one concrete example. We have spoken of Ancient Rome, which gloried in titles such as the 'city of cities' and the 'hub of the universe.' During the Middle Ages the city declined, and by 1417 the old metropolis had only 17,000 inhabitants."

　　"Not much more than Lillesand, where Hilde lives."

　　"The Renaissance humanists saw it as their cultural duty to restore Rome: first and foremost, to begin the construction of the great St. Peter's Church over the grave of Peter the Apostle. And St. Peter's Church can boast neither of moderation nor restraint. Many great artists of the Renaissance took part in this building project, the greatest in the world. It began in 1506 and lasted for a hundred and twenty years, and it took another fifty before the huge St. Peter's Square was completed."

　　"It must be a gigantic church!"

　　"It is over 200 meters long and 130 meters high, and it covers an area of more than 16,000 square meters. But enough about the boldness of Renaissance man. It was also significant that the Renaissance brought with it a new view of nature. The fact that man felt at home in the world and did not consider life solely as a preparation for the hereafter, created a whole new approach to the physical world. Nature was now regarded as a positive thing. Many held the view that God was also present in his creation. If he is indeed infinite, he must b present in everything. This idea is called pantheism. The medieval philosophers had insisted that there is an insurmountable barrier between God and the Creation. It could now be said that nature is divine——and even that it is 'God's blossoming.' Ideas of this kind were not always looked kindly on by the church. The fate of Gior-dano Bruno was a dramatic example of this. Not only did he claim that God was present in nature, he also believed that the universe was infinite in scope. He was punished very severely for his ideas."

　　"How?"

　　"He was burned at the stake in Rome's Flower Market in the year 1600."

　　"How horrible …… and stupid. And you call that humanism?"

　　"No, not at all. Bruno was the humanist, not his executioners. During the Renaissance, what we call anti-humanism flourished as well. By this I mean the authoritarian power of State and Church. During the Renaissance there was a tremendous thirst for trying witches, burning heretics, magic and superstition, bloody religious wars——and not least, the brutal conquest of America. But humanism has always had a shadow side. No epoch is either purely good or purely evil. Good and evil are twin threads that run through the history of mankind. And often they intertwine. This is not least true of our next key phrase, a new scientific method, another Renaissance innovation which I will tell you about."

　　"Was that when they built the first factories?"

　　"No, not yet. But a precondition for all the technical development that took place after the Renaissance was the new scientific method. By that I mean the completely new approach to what science was. The technical fruits of this method only became apparent later on."

　　"What was this new method?"

　　"Mainly it was a process of investigating nature with our own senses. Since the fourteenth century there had been an increasing number of thinkers who warned against blind faith in old authority, be it religious doctrine or the natural philosophy of Aristotle. There were also warnings against the belief that problems can be solved purely by thinking. An exaggerated belief in the importance of reason had been valid all through the Middle Ages. Now it was said that every investigation of natural phenomena must be based on observation, experience, and experiment. We call this the empirical method."

　　"Which means?"

　　"It only means that one bases one's knowledge of things on one's own experience——and not on dusty parchments or figments of the imagination. Empirical science was known in antiquity, but systematic experiments were something quite new."

　　"I guess they didn't have any of the technical apparatus we have today."

　　"Of course they had neither calculators nor electronic scales. But they had mathematics and they had scales. And it was now above all imperative to express scientific observations in precise mathematical terms. 'Measure what can be measured, and make measurable what can-not be measured,' said the Italian Galileo Galilei, who was one of the most important scientists of the seventeenth century. He also said that the book of nature is written in the language of mathematics."

　　"And all these experiments and measurements made new inventions possible."

　　"The first phase was a new scientific method. This made the technical revolution itself possible, and the technical breakthrough opened the way for every invention since. You could say that man had begun to break away from his natural condition. Nature was no longer something man was simply a part of. 'Knowledge is power,' said the English philosopher Francis Bacon, thereby underlining the practical value of knowledge—— and this was indeed new. Man was seriously starting to intervene in nature and beginning to control it."

　　"But not only in a good way?"

　　"No, this is what I was referring to before when I spoke of the good and the evil threads that are constantly intertwined in everything we do. The technical revolution that began in the Renaissance led to the spinning jenny and to unemployment, to medicines and new diseases, to the improved efficiency of agriculture and theimpoverishment of the environment, to practical appliances such as the washing machine and the refrigerator and pollution and industrial waste. The serious threat to the environment we are facing today has made many people see the technical revolution itself as a perilous maladjustment to natural conditions. It has been pointed out that we have started something we can no longer control. More optimistic spirits think we are still living in the cradle of technology, and that although the scientific age has certainly had its teething troubles, we will gradually learn to control nature without at the same time threatening its very existence and thus our own."

　　"Which do you think?"

　　"I think perhaps there may be some truth in both views. In some areas we must stop interfering with nature, but in others we can succeed. One thing is certain: There is no way back to the Middle Ages. Ever since the Renaissance, mankind has been more than just part of creation. Man has begun to intervene in nature and form it after his own image. In truth, 'what a piece of work is man!' "

　　"We have already been to the moon. What medieval person would have believed such a thing possible?"

　　"No, that's for sure. Which brings us to the new world view. All through the Middle Ages people had stood beneath the sky and gazed up at the sun, the moon, the stars, and the planets. But nobody had doubted that the earth was the center of the universe. No observations had sown any doubt that the earth remained still while the 'heavenly bodies' traveled in their orbits around it. We call this the geocentric world picture, or in other words, the belief that everything revolves around the earth. The Christian belief that God ruled from on high, up above all the heavenly bodies, also contributed to maintaining this world picture."

　　"I wish it were that simple!"

　　"But in 1543 a little book was published entitled On the Revolutions of the Celestial Spheres. It was written by the Polish astronomer Nicolaus Copernicus, who died on the day the book was published. Copernicus claimed that it was not the sun that moved round the earth, it was vice versa. He thought this was completely possible from the observations of the heavenly bodies that existed. The reason people had always believed that the sun went round the earth was that the earth turns on its own axis, he said. He pointed out that all observations of heavenly bodies were far easier to understand if one assumed that both the earth and the other planets circle around the sun. We call this the heliocentric world picture, which means that everything centers around the sun."

　　"And that world picture was the right one?"

　　"Not entirely. His main point——that the earth moves round the sun——is of course correct. But he claimed that the sun was the center of the universe. Today we know that the sun is only one of an infinite number of stars, and that all the stars around us make up only one of many billions of galaxies. Copernicus also believed that the earth and the other planets moved in circular orbits around the sun."

　　"Don't they?"

　　"No. He had nothing on which to base his belief in the circular orbits other than the ancient idea that heavenly bodies were round and moved in circles simply because they were 'heavenly.' Since the time of Plato the sphere and the circle had been considered the most per-fect geometrical figures. But in the early 1600s, the German astronomer Johannes Kepler presented the results of comprehensive observations which showed that the planets move in elliptical——or oval——orbits with the sun at one focus. He also pointed out that the speed of a planet is greatest when it is closest to the sun, and that the farther a planet's orbit is from the sun the slower it moves. Not until Kepler's time was it actually stated that the earth was a planet just like other planets. Kepler also emphasized that the same physical laws apply everywhere throughout the universe."

　　"How could he know that?"

　　"Because he had investigated the movements of the planets with his own senses instead of blindly trusting ancent superstitions. Galileo Galilei, who was roughly contemporary with Kepler, also used a telescope to observe the heavenly bodies. He studied the moon's craters and said that the moon had mountains and valleys similar to those on earth. Moreover, he discovered that the planet Jupiter had four moons. So the earth was not alone in having a moon. But the greatest significance of Galileo was that he first formulated the so-called Law of Inertia."

　　"And that is?"

　　"Galileo formulated it thus: A body remains in the state which it is in, at rest or in motion, as long as no external force compels it to change its state."

　　"If you say so."

　　"But this was a significant observation. Since antiquity, one of the central arguments against the earth moving round its own axis was that the earth would then move so quickly that a stone hurled straight into the air would fall yards away from the spot it was hurled from."

　　"So why doesn't it?"

　　"If you're sitting in a train and you drop an apple, it doesn't fall backward because the train is moving. It falls straight down. That is because of the law of inertia. The apple retains exactly the same speed it had before you dropped it."

　　"I think I understand."

　　"Now in Galileo's time there were no trains. But if you roll a ball along the ground——and suddenly let go……"

　　"…… it goes on rolling ……"

　　"…… because it retains its speed after you let go."

　　"But it will stop eventually, if the room is long enough."

　　"That's because other forces slow it down. First, the floor, especially if it is a rough wooden floor. Then the force of gravity will sooner or later bring it to a halt. But wait, I'll show you something."

　　Alberto Knox got up and went over to the old desk. He took something out of one of the drawers. When he returned to his place he put it on the coffee table. It was just a wooden board, a few millimeters thick at one end and thin at the other. Beside the board, which almost covered the whole table, he laid a green marble.