He is a man of striking middle age, famously arrogant and arrogantly famous; she, a woman in first flower, fair-haired and round of countenance, the sort of face Vignaud would put on canvas 700 years later.

The man has lured her here. And she has followed, willingly. He moves toward her.

It is 1119, the waning days of a bad time and the beginning of a better one, and at the center of this rebirth are men like this one: He is Pierre Abelard, a renowned French philosopher and theologian. He has moved into this richly furnished home, the house of an elder of his church, to school this young woman in the ways of the Lord, the mysteries of eternity, the richness of the examined life. Her name is Heloise. She is a rarity, a female of intellectual accomplishment. This, to a man like Abelard, is most seductive.

He is smitten.

No, not smitten. He is lost in lust.

"I was utterly aflame with my passion for this maiden," he would later write.

What Heloise feels is a churning desire. She admits she would follow him "into Hell itself," if necessary.

What Abelard feels is monstrous.

Its flames lick at his vitals and threaten his soul. It is not because of his exalted position or her tender age; at 17, she is considered well ripened for courtship. It is because love, this sort of passionate love, is prohibited of all men. Abelard knows this because his church is quite clear on the subject: To feel intensely for another human being, even one's spouse, is a human frailty. It is a betrayal of God, for whom one's love must be pure and perfect and in competition with nothing earthly. The Roman Catholic Church says so.

This is love in the Western world early in the millennium. If it is there, it dare not speak.

Here they are, alone together, Abelard and Heloise. What will he do?

Let him tell it:

"Our kisses far outnumbered our reasoned words. Our hands sought less the book than each other's bosoms; love drew our eyes together far more than the lesson drew them to the pages of our text."

A baby was born. Heloise and Abelard married in secret, though she said she would rather be his lover than his wife. Heloise's uncle and protector, Canon Fulbert, was horrified. What happened next made the story of Abelard and Heloise the first great love story of the millennium, perhaps even the greatest of all. The best love stories are invariably tragedies.

Canon Fulbert took his revenge. "One night, while I, all unsuspecting, was asleep in a secret room in my lodgings, they broke in with the help of one of my servants, whom they had bribed," Abelard wrote. "They cut off those parts of my body with which I had done that which was the cause of their sorrow."

Emasculated, Abelard became a recluse, teaching theology. Heloise became a nun, though she claimed she loved Abelard more than God Himself. She lived under the heavy robes of the convent with a burning desire for his flesh and what was left of the memories of their furtive meetings.

They never saw each other again.

Always respected for his scholarship, Abelard was finally accepted into the church as a perfect man. At last, he wrote, he was deemed free to conduct himself "for the sole love of God."

Rapturous Love

Social historians have suggested that the last millennium saw the birth of the concept of romantic love; that before then, through much of the world, love and ardor was suspect; that it did not ordinarily accompany sex; that the coupling of man and woman was largely utilitarian; that one married and procreated for replenishment of the work force, for duty to God, for personal vanity. This is intriguing, but wrong. For evidence one can look as far back as the Old Testament. The Song of Songs. You know, the hot one.

King Solomon is said to have written this book, the only book in the Bible that does not expressly mention God. It is filled with the rapture of erotic love between a man and a woman.

The Song of Songs may be the oldest black woman's love song known.

"I am black and beautiful," a young woman exults to her lover. The lovers in Song of Songs revel in each other's body taste, touch and smell.

"How fair and how pleasant art thou, o love, for delights! This thy stature is like to a palm-tree, and thy breasts to clusters of grapes, And I said I will climb up into the palm-tree, I will take hold of the branches thereof, and let thy breasts be as clusters of the vine, and the smell of thy countenance like apples, and the roof of thy mouth like the best wine that glideth down smoothly for my beloved, moving gently the lips of those that are asleep. . . . I opened to my beloved. "

Nearly unprintable stuff!

At the start of the last millennium, the Christian church would reconcile the heat of this biblical book thus: The story was allegory, a tale of religious devotion in which the love of God merely appears to be the love of a man.

You be Solomon. You be the judge.

But remember this:

Solomon had a harem. One thousand wives and concubines.

Polite Love

It is not what humans feel for one another that has changed over time; like all species we were made to survive, and to survive we must not only lust, but feel an intensity and depth of emotion that makes us procreate, then keeps us together long enough to protect our young. What has changed profoundly over the millennium is how our societies -- their political and religious institutions and their writers of literature -- set the standards for the conduct of love.

In Europe after the time of Abelard, a new concept of love was born, unique to its time and place. Sociologists call it "courtly love," because it is thought to have arisen in the influential courts of Eleanor of Aquitaine. Eleanor was a woman of romantic imagination whose 12th-century reign began at the age of 15 and would, amazingly, encompass both France (as queen to Louis VII) and England (as queen to Henry II).

Inspired by Arab romantic poets, troubadours would pollinate stories of courtly love throughout Western Europe. They would find an audience. Feudal conflicts and Viking raids were lessening. Men of war had time for love.

Courtly love was strange. It would eventually evolve into the modern Western concept of love and marriage, once the kinks were ironed out. The kinks would take a lot of ironing, because they were pretty kinky.

Courtly love seems to represent an early, uneasy truce between the urges of man and the constraints of the church. It acknowledges the inevitability of sexual passion, in a somewhat idealized and adolescent sense.

One loved with a rapture bordering on lunacy.

One loved with a nobility of purpose bordering on sainthood.

One loved with a courtesy bordering on foppery.

One loved with an obsession bordering on stalking.

If one was a man, one loved solicitously, like a sap -- leaping to satisfy every whim of one's lover, obedient to her most trivial requests, cringing at her slightest rebuke. If one was a woman, one engaged in a great deal of swooning.

One loved adulterously. The courtly ideal did not cotton to the institution of marriage, which existed for the simple banality of procreation. This was quite plain: In 1175 in England, Andreas Capellanus, better known as Andrew the Chaplain, wrote: "We declare, and we hold as firmly established that love cannot exert its powers between two people who are married to each other."

And last, most remarkably, courtly love was largely chaste. It tended to be unrequited. Heroically unrequited. In literature, Guinevere was married to King Arthur, but she pined for Lancelot. Their love was pure because it was unsullied by sexuality. (And when, finally, they acted on their impulses, the ensuing scandal helped bring down Camelot.) But courtly love was not a thing of fiction alone.

Obsessive Love

When he first saw her, he was an old 9 and she was a young 9. Her skin was pale and white as porcelain, fragile as an eggshell. Her thick red hair hung over her shoulders. She wore a blood-red robe bound so tightly around her chest it made her look like a Christmas-tree angel.

And at that very moment, the Earth stopped for him. He began to tremble. He thought he saw God for a moment. Isn't God supposed to be love? Or is it the other way around? And something inside him spoke these words: "Here is a God stronger than I, who comes to rule over me."

This was Dante Alighieri, the great Italian writer. She was Bice Portinari, though he called her Beatrice. The year was 1274 in Florence, and romantic love had evolved this far: It was accepted by the church, but with suspicion. There are rules, courtly rules. Love but don't touch.

Dante just walked away.

They remained strangers. Nine years after they first saw each other as children, they saw each other again. They were teenagers by then. It was 3 p.m. The afternoon light bathed the street, and hit her just right. She, wearing white, stood between two ladies of noble bearing. We know all this because Dante would write of it, in lush detail, in a book titled "La Vita Nuova."

From across the street, Beatrice looked at Dante.

And the Earth stopped again, and he could not speak.

What did he do? Did he return the greeting and insinuate his way into her company?

"I became so ecstatic that, like a drunken man, I ran away from everyone and I sought the loneliness of my room," he wrote.

Love had made him a fool. Beatrice and her friends laughed at him. Dante did not know Beatrice, but lived in fear of her death.

"I began, like a person who is delirious, to be tormented by these fantasies," he wrote. "I seemed to see the sun grow dark and stars turn to such a color that I thought they were weeping; birds flying in the air fell dead, and the earth trembled with great violence."

There is no record of whether the sun extinguished itself or the birds thudded from the skies when Beatrice breathed her last in 1290, still in her twenties. But we know from Dante's writings that though he had both wife and mistress, his love for the always and forever unattainable Beatrice did not die until he did, three decades later.

Courtly love was a strange ideal, no doubt. But it served as a turning point, because it acknowledged what had not before been acknowledged, at least for 1,000 years: that there could occur between men and women a lasting passion, and that it was noble, and that two people who are meant for each other are meant for each other for all time and to the exclusion of all others. This concept would define romantic love for hundreds of years. It would inform the works of Shakespeare and the modern poets. It would guide courtship and marriage through the ages of Elizabeth and Victoria, through times of revolution and early industrialization. It would not begin to be dismantled until the second half of the final century of the millennium, and America would lead the way.

But that would come much later, after the ideal of courtly love had begun to metamorphose into something different, something truer. This may well have begun, as so many things did, in Africa.

Blind Love

At the foot of the great silk cotton tree in front of the palace beside the Niger River sat two men, one a king, the other a hunter, a stranger to the kingdom. It was 1210. The man in rich robes was Maghan Kon Fatta, who ruled the kingdom of Kangaba, or Mali. Fatta was a strong king, well liked, dignified and handsome.

The hunter, it is said, withdrew from his bag 12 cowrie shells. This man was left-handed -- perhaps a sign of evil? -- and he shuffled the cowries and threw them like dice. He saw something in the pattern of their scattering. He knew what it meant.

How does one tell a king such a thing? The hunter just gulped and said it: that the king's successor would come not from any of his wives, but from a wife he had yet to meet, the ugliest woman he would ever see. She had a hump on her back and hideous eyes. "This is the woman you must marry, sire," said the hunter, "for she will be the mother of him who will make the name of Mali immortal forever."

The story of the hunter-soothsayer may be legend, but possibly it is true, because what followed is historical fact: A grotesquely deformed woman did visit the kingdom, and Fatta did take her as his wife, on the first Wednesday of a new moon. So repulsed was he by her appearance that he suspected she might be more beast than human; part buffalo, perhaps. It took days to consummate the marriage. Eventually, Fatta came to love this woman more than any other, for her strength of character. The son she bore him became Fatta's successor -- Sundiata, the original Lion King, whose quarter-century reign spanned the glory years of Mali.

The story has echoes that carried great distances, like a drum in a forest.

Love is something meant to be.

Love is deeper than the skin.

From love can arise great things.

Monumental Love

It stands 240 feet high, rising on a base of red sandstone from the banks of the Jumna River in Agra, in northern India. It is topped with an enormous tapered dome of white marble -- among the most recognizable structures ever built. Certainly the most romantic.

Twenty thousand men and 1,000 elephants were deployed to build a "teardrop on the cheek of time," the Taj Mahal, in 1631.

It is considered today a miracle of engineering and a triumph of architecture, but its most enduring value is not man-made. The Taj Mahal is a memorial to love. It is not an extravagant gift from a rich man to his wife, for her love in return. There is no commerce here, real or implied.

Persia's Shah Jahan built this as a mausoleum for his wife, Mumtaz Mahal, when she died giving him his 14th child. Her death so wounded him that his hair and beard turned ghost-white.

Before she died, she had asked of Jahan four things only: that he be kind to their children, that he remarry, that he build her a tomb, and that he visit it every year on the anniversary of her death.

Jahan kept the vows he could. Some, he could not. Between Jahan and his son, Aurangzeb, grew a terrible enmity. In 1658 Aurangzeb overthrew his father and imprisoned him in the Agra fort.

For eight years, Jahan remained a captive of his son, unable to leave even for his promised yearly pilgrimage to his wife's tomb, a few hundred feet away. He died in captivity. As he drew his final breaths, it is reported that he kept his eyes fixed out the window, at the Taj Mahal.

Stalker Love

The power of courtly love, and its inherent weakness, collided in the body of one man, the 19th-century French essayist Marie Henri Beyle, known as Stendahl. What would come of it would prove a window into the future.

Stendahl met Mathilde Viscontini Dembowski in Milan in 1818. She was, to his thinking, beautiful. She had big eyes, a broad, flawlessly clear forehead, a pouty little mouth and chubby fingers. Plus, a protruding belly on which to rest her arms.

Perfect, he believed.

He loved her.

She detested him.

He loved her.

She fled him.

He thought she was life itself.

She thought he might be a French spy.

He followed her one day, disguising himself in an overcoat and dark-green glasses. She recognized him. He was embarrassed. He pretended not to know her. But then he just "bumped" into her the very next day in a meadow where she took daily walks. He swore it was by accident. She was angry. She ordered him away, forever.

Stendahl didn't take rejection well. He wrote a riveting psychological study of love. He'd studied only himself, but his subject proved exceedingly interesting and complex. Angry, too.

"If you are sure that a woman loves you," Stendhal wrote, you "endow her with a thousand perfections and to count your blessings with infinite satisfaction. In the end you overrate wildly."

Stendahl postulated various types and stages of love. Love, he said, progresses like a sort of crystallization process, similar to what happens when you throw a stick into a salt mine:

Two or three months after the branch is pulled up, it is covered with a shining deposit of crystals "studded with a galaxy of scintillating diamonds. The original branch is no longer recognizable." If love is to be complete, Stendahl said, it is a discovery of the other person and a corresponding loss of self.

And yet Stendahl envisioned something else, an alternative way to love. He called it Vanity Love: where the love of self is central, and demands another simply to complement it.

Stendahl was, it turns out, quite ahead of his time.

The final three centuries of the millennium saw an evolution of the importance of the individual. Man fought and won his freedom in France and England and the United States. His attention turned to human rights. Scientists wrested from religion and superstition the right to explain the workings of the world, and man's place in it.

The concept of the self, in love, trailed a bit. But it finally emerged, fretfully, groaning under its load -- a little embarrassing, like a creaking bed.

Love of Country

The Duke of Kent rolled over, next to his French mistress. He picked up the morning newspaper and saw something that would change the world.

The duke was a long, heavy man with prominent eyes and a fringe of hair clinging to his balding head. Still, he was considered by some to be handsome, even attractive. Especially to his mistress, Madame de St. Laurent, who loved him as he loved her. In 27 years they dined apart not a single day.

It was a cold morning in December of 1817. The duke's niece, Princess Charlotte, had just died in childbirth, after 50 hours of labor. Charlotte was to have inherited the throne, and her child was to be the future of England.

With the death of the beloved princess, the nation fretted. Who would succeed Prince George, Charlotte's father? The king, George III, was certifiably mad, locked away in a castle at Windsor. Prince George was his firstborn son, and king-to-be, and Charlotte was George's only child.

George would have no more children. He was 55 and separated from his wife, Caroline of Brunswick. He had eaten and drunk so much that he was grossly fat.

Hope lay in the dukes, Prince George's brothers. But they were a sorry lot: old and dissolute:

The Duke of York was 54, married to a woman who disliked all things carnal. She was known to lie fully dressed on a couch, while a lady-in-waiting read to her all night. She lived surrounded by at least 40 dogs.

The Duke of Cumberland was 46, but he looked like an ogre and women detested him. He had no children.

The Duke of Clarence was 52. He had a fleet of bastard children, but no legitimate heirs.

And then there was the Duke of Kent -- old, but relatively robust. He could surely father a child. He was unmarried, technically. What he saw in the newspapers that morning in 1817 was an editorial begging him, for the good of his country, to cast away his mistress and take a proper bride, and save the monarchy.

The duke was in beastly debt, and as sire to the new heir he would be in line for a generous allowance. This no doubt factored into his decision. But in the end, it came to this: He had been asked to give up the woman he loved -- and he most surely loved her -- for the sake of his country.

It was that sort of era. People did things like that.

With a heavy heart, the duke dispatched his lover to Paris, where she became known as the Comtesse de Montgenet. In May 1818, the duke proposed to the Princess of Leiningen of Germany, a young woman chosen for her bloodlines and fertility. He had only glimpsed her once, and had formed no opinion whatsoever.

The duke never saw Madame de St. Laurent again, although they corresponded incessantly. He would write to friends, discreetly urging them to check on her and report back. He worried about her health and her feelings, warning visitors not to make any mention of the new duchess.

The duke felt a longing, and, no doubt, a guilt. He wrote: "Although an intimacy now of eight months with the Duchess has attached me sincerely to her, in every point that regards the Countess of Montgenet we must never lose sight that our unexpected separation arose from the imperative duty I owed to obey the call of my family and my Country to marry."

A year later, the duke's German bride gave birth to a sturdy baby girl at Kensington Palace. It was May 24, 1819. She would be their only child, heir to the British throne. They named her Victoria.

Victoria's reign would last more than half a century, and become synonymous with an era of prudishness and sexual repression. This was in many ways misleading and unfair. Victoria's marriage to her Prince Albert was one of the great love stories of its time. The queen's insistence upon wearing black from the moment of his death to the moment of hers, 40 years later, was an astonishing monument -- in its own primly British way every bit as magnificent as the Taj Mahal.

Selfless Love

Standing as stiff bookends to the reign of Victoria were the story of the Duke of Kent -- the man who gave up his love for the sake of his country -- and the more familiar story of the man who gave up his country for the sake of his love. It was a telling progression.

It was now the 1900s, and there was a flowering of the sense of self, particularly in matters of love. People allowed themselves more choices.

The man was Edward, Prince of Wales, soon to become King of England. She was Wallis Warfield Simpson, a rather plain woman from Baltimore who was working on her second marriage.

Edward saw her at a party one night. Her eyebrows were plucked. She wore an unattractive hairstyle parted in the middle. And on top of her plain dress, incongruously, she wore big, real jewels in Cartier settings. She was witty. She protested ignorance of politics and claimed to be inexperienced in worldly affairs. As other women greeted her, she turned her cheek with appropriate dignity to receive a kiss, but she did not return any. She walked into a room as though she expected to be curtsied to.

It was in the autumn of 1930, at Lady Furness's house in London. The lady took Mrs. Simpson to the prince. It was not, as some said, love at first sight.

It was not until months later, when the two slipped away from a party to take a short trip on a yacht, that Simpson and the prince, as she would later discreetly put it, "crossed the line that marks the indefinable boundary between friendship and love."

To her astonishment ("In my own country," Simpson once wrote of her unremarkable appearance, "I would have been considered securely on the shelf.") the prince lavished her with jewels. At his slightest wish, trains were delayed, yachts materialized, the best suites in the finest hotels were flung open, airplanes stood waiting.

On Jan. 20, 1936, Edward's father, George V, died. And Edward the bachelor became Edward VIII.

He continued to see Simpson, who was still married. They were photographed sunbathing, scandalous for a king. She knew he would never be able to marry her and told him she would leave. He threatened suicide. Soon thereafter, she divorced and they announced their engagement.

Parliament was up in arms. Their king could not marry a divorcee. Edward was given an ultimatum: the woman or his throne.

On Dec. 10, 1936, Edward made his choice.

"I have found it impossible to carry on the heavy burden of responsibility and to discharge my duties of King as I would wish to do without the help and support of the woman I love."

Demoted to duke, Edward married Wallis in a simple ceremony in June 1937. The royal family did not attend. The day after the wedding, Edward reportedly looked at his new wife and said, "Now, what shall we do?"

Live together until death, as it happens. It was quite a durable marriage, given over to parties and revelry and other relentlessly trivial pursuits, but anchored by the monumental gravity of what they had done.

Love of Self

The rest of the 20th century, in the United States and elsewhere, became a time of experimentation in matters of love. Homosexuals began to declare theirs openly and without embarrassment or apology. Innovations in contraception reduced risks and vastly (and globally) increased the practice of casual, recreational sex. But mostly the 1900s have been the century of divorce, where the operative notion of love -- the ideal of courtly love -- seemed to have metamorphosed to this: Love is grand, and powerful, and noble, but it is not forever. It is not a mysterious force that binds two people for all eternity. It can end, and when it does, it's best to split apart. Even if one of you is heir to the throne, like Chuck and Di. Even if you have been married seemingly forever, like Edward and Joan Kennedy. Liz and Dick divorced twice.

As the millennium of science draws to a close, the final words on love belong perhaps to the scientists, who say they have figured out, at long last, what it is that cost Abelard his manhood, and bedeviled Dante, and filled the pen of Shakespeare, and drove Stendahl halfway mad, and built the grandest tomb on Earth, and forfeited a crown.

It's called phenylethylamine. It's a natural amphetamine that gathers in the synapses in the neurons of the limbic system of the cerebral cortex, and has been shown to be present in high concentrations when persons experience feelings commonly expressed as love or extreme affection.

The more phenylethylamine, the more you love. When it disappears, you suffer withdrawal.

That explains everything.

Doesn't it?