I was now sitting at the heart of the area in which Descartes loved most to live whenever he was in Paris for longer stays—the then-as-now-fashionable district of Saint-Germain-des-Pres. Richard was talking fast about Descartes and history and Paris, but we were too often interrupted by the perpetual ring of his cell phone. I looked at the ancient church in front of us. I knew it was very old—its construction began in the sixth century. The church has a graceful tower, dating to the tenth century and still in its original state. It has a rustic kind of beauty, seen more often in churches in the French countryside, and in fact it used to be out in the fields, outside the city walls—hence the designation “des Pres.” And I knew something else about this church: inside it is a crypt containing the remains of Rene Descartes. But the body of the great philosopher and mathematician—so revered by the French—lacks a head. Descartes' skull, or rather a skull purported to be that of the philosopher, is displayed elsewhere in Paris. Nothing about Descartes is simple, and nothing is what it seems, as I learned in my quest to understand Descartes and to uncover his secrets.
Prologue
Leibniz's Search in Paris
ON JUNE 1, 1676, GOTTFRIED WILhelm Leibniz, who would become known as one of the greatest mathematicians of all time and who—along with Newton, who worked independently in England— would be credited with the discovery of the calculus, stepped off a carriage in front J of a house in Paris, climbed up a set of stairs, and knocked on a heavy wooden door.
Leibniz had arrived in Paris a few years earlier from Hanover, in his native Germany. He was on a diplomatic mission on behalf of his patron, a German nobleman. But personally, Leibniz was on a search for Descartes' hidden writings. He had heard that when Descartes died, in Stockholm in 1650, he had left behind a locked box containing writings that he never intended to publish and had kept secret throughout his life. Leibniz knew that these writings were kept somewhere in the French capital, and over three and a half years in Paris, Leibniz made every effort to locate this treasure. Finally, using a network of connections, Leibniz was able to obtain the name and address of Claude Clerselier (1614-84), a man who had been a friend of Descartes and an editor and translator of his works.
Leibniz learned that a quarter of a century earlier, Clerselier received Descartes' hidden manuscripts as a present from his brother-in-law Pierre Chanut (1601-62), who had been France's ambassador to Sweden and a confidant of Descartes during the few months he served as philosophy teacher to Queen Christina of Sweden before he died.
Some time after Descartes' death, Ambassador Chanut loaded the box containing Descartes' hidden manuscripts onto a ship in Stockholm headed for France. After long delays en route, the cargo was unloaded sometime in 1653 at the French port of Rouen. The box was then reloaded onto a boat that was to take it up the Seine River to Paris. But just as the boat entered Paris and was passing by the palace of the Louvre, it capsized and sank. The sealed box containing Descartes' manuscripts remained submerged for three days. Then, miraculously, it disentangled itself from the wreckage and was found on the bank of the river some distance downstream.
Upon hearing this news, Clerselier—who had been expecting the precious cargo for a long time and had sadly just given up hope of ever seeing the manuscripts after he heard that the boat had capsized— rushed to the river with all his servants and ordered them to retrieve the papers quickly. He instructed his servants to spread the parchment sheets of Descartes' manuscripts on tables in his house to dry. The servants were illiterate, and found it difficult to reassemble the manuscripts. But Clerselier worked hard to save Descartes' hidden writings and spent many years reading the manuscripts and putting them in order. There was, however, one notebook whose content he could not understand.
The elderly man opened the door slightly, but seeing someone he did not recognize, shut it again. “Please,” pleaded the young man from behind the locked door, “please read this letter,” and he thrust in through a reopened crack in the door a letter of introduction from the duke of Hanover, asking whoever was shown it to offer all help to its bearer.
After quickly reading the letter, Clerselier opened his door and motioned Leibniz in. Clerselier was a possessive man, and had been jealously guarding Descartes' writings. He viewed himself as the protector of his late friend's secrets. Clerselier listened intently as Leibniz explained his urgent and unusual need to see the documents. Upon hearing the story, he understood that this young man's future and reputation might well depend on the content of Descartes' hidden writings. So reluctantly, and despite his inclination to the contrary, Clerselier agreed to let Leibniz see Descartes' work, and even to copy it.
Leibniz sat down, opened a manuscript, and read:
PREAMBLES
Fear of God is the beginning of wisdom. The actors, called to the scene, in order to hide their flaming cheeks, don a mask….
But after reading Descartes' description of his hope of discovering science all on his own, and of “advancing masked” through life, Leibniz read the following as the manuscript continued:
MATHEMATICAL TREASURE OF POLYBIUS THE COSMOPOLITAN
Providing the reader with the true means of resolving all the difficulties of this science; it is demonstrated that, on these difficulties, the human spirit can find nothing more. This, to shake off idle chatter, and to dismiss the recklessness of some who promise to demonstrate in all the sciences new miracles.
Leibniz understood that Descartes had planned to write a book about an important mathematical discovery using a pseudonym. Rene Descartes would be Polybius the Cosmopolitan. Leibniz paused for a moment. Then he continued to peruse the unusual document; but what he read next startled him:
Offered, once again, to the erudite scholars of the entire world, and especially to G. F. R. C.
In the copy he made of the manuscript, Leibniz added a parenthetical word, making it read:
G. (Germania) F. R. C.
He did not need to annotate the acronym “F. R. C.” He knew it well… perhaps too well. Leibniz felt a quiver run down his spine as he realized that an invisible secret bond linked him with the late French philosopher.
Looking carefully at the manuscripts in front of him, Leibniz understood that the Preambles and the Olympica, which announced Descartes' “admirable discovery” but did not give the discovery itself, were only fragments designed to introduce the actual work in which the truth Descartes did not disclose in these manuscripts was exposed. But what was the work, and where was it? As he was about to find out, Leibniz was now very close to Descartes' deepest secret, the discovery nearest to Descartes' heart—one that would need to be veiled with a pseudonym, mysterious language, and bizarre, mystical notation.
“Yes, there is one more item,” said the elderly gentleman after Leibniz had finished five days of copying and eagerly asked him if there was anything else. “But nobody else has ever seen it before. It's a notebook—his secret notebook.” Then he added, “But I don't think you would understand it anyway. I've worked on it for years, but nothing in it, symbols, drawings, formulas, makes any sense at all. It is completely coded.”
Leibniz pleaded, and again explained his desperate need to learn everything he could about the hidden work of Descartes. He promised that he would keep the secret, whatever it was that was hidden in Descartes' pages. Finally, Clerselier relented, but imposed tight restrictions on the access to this notebook.
Descartes' notebook consisted of sixteen parchment pages. It contained bizarre notation. Some of the symbols resembled those associated with alchemy and astrology—not the characters usually found in writings on mathematics. And next to them were strange, obscure figures. Then there were seemingly incomprehensible sequences of numbers. What did all these mean?
Working intently and very fast—perhaps furtively, for we don't know exactly what were the conditions Clerselier had imposed when he finally allowed Leibniz to see the notebook—Leibniz had to decipher Descartes' code while at the same time doing the copying. He
was able to copy only one and a half pages by the time he had to stop his work. Part of Leibniz's copy of Descartes' secret notebook is shown on page 15.
A page from Leibniz's copy of Descartes' secret notebook
Some years after Leibniz made this copy, Descartes' original notebook disappeared forever. And for over three centuries, no one could understand the meaning of the copy Leibniz had made of Descartes' secret notebook.
What the bizarre symbols, including 24 meant, and what the sequences of numbers—
4 6 8 12 20 and 4 8 6 20 12
—signified, remained a deep mystery.
Why did Descartes keep a secret notebook? What were its contents? And why did Leibniz feel compelled to travel to Paris, seek out Clerselier, and copy pages from Descartes' notebook?
Chapter 1
The Gardens of Touraine
JUST BEFORE RENÉ DESCARTES WAS born, on March 31, 1596, his mother, Jeanne Brochard, took an action that may well have altered the course of Western civilization. For like Julius Caesar crossing the Rubicon in 49 B.C., Jeanne Brochard crossed the Creuse River, which lay between her family home, in the region of Poitou, and the small town of La Haye, which lies in the region of Touraine, in western central France.
The Descartes family had originated in Poitou and had lived for many years in the town of Chatellerault, about twenty-five kilometers south of La Haye. Descartes' parents, Joachim Descartes and Jeanne Brochard, who were married on January 15, 1589, owned a stately mansion in the center of Chatellerault, at 126 rue Carrou-Bernard (today's rue Bourbon).
The Descartes family mansion in Chatellerault
Joachim Descartes was the councillor of the Parliament of Brittany, and this important job kept him away in distant Rennes. Jeanne needed her mother's help in birthing the baby, and this is why she traveled north and across the river to Touraine to give birth to Rene Descartes in her mother's house in La Haye. Sometime later, once she had recovered, she returned to Chatellerault. Despite this accident of birth, throughout his life, Rene's friends would often call him Rene le Poitevin—Rene of Poitou.
Descartes' grandmother's house (now the Descartes Museum)
The regions of Poitou and Touraine include pastoral farmlands that have been cultivated since antiquity. There are low hills, many of which are forested, and rich flatlands, irrigated by rivers that cut through this fertile land. Cows and sheep graze here, and many kinds of crops are grown. La Haye is a small town of stone houses with gray roofs. At the time of Descartes, the population of the town numbered about 750 people.
Chatellerault is a larger, more genteel town than La Haye, with wide avenues and an elegant city square, and it serves as the hub of rural life in the region. Because this part of France is so fertile and rich in water and agricultural resources, the people who live here are well off. North of La Haye one can still visit the beautiful chateaus of the Loire Valley, as well as forests and game reserves, which existed at the time of Descartes. The chateaus, many of them restored to their original state, with lavish fifteenth- and sixteenth-century furnishings and surrounded by sculpted gardens, give us a feel for the life of the rich at the time of Descartes.
While the regions of Poitou and Touraine are similar in their topography, scenery, and the way the towns and villages are laid out, there was one important difference between them. While Poitou was mainly Protestant, Touraine was mostly Catholic. We know that in the fifteen years from 1576 to 1591, there were only seventy-two Protestant baptisms in La Haye. This significant religious difference between the two regions would affect the life of Rene Descartes. For this accident of birth—being born, and later also raised, in a strongly Catholic region while his family hailed from a Protestant one—would exert a significant impact on Rene's personality, thus influencing his actions throughout his life and determining the course of development of his philosophical and scientific ideas and the way he divulged them to the world.
Descartes lived in a century that knew severe tensions, including wars, between Catholics and Protestants. The fact that he was born in a Catholic region and would be raised by a devout Catholic governess, while many of his family's friends and associates in Poitou were Protestants, contributed to Descartes' natural secretiveness. It also made him, as an adult, much more concerned about the Catholic Inquisition than perhaps he should have been, and not worried enough about the persecution he could face from Protestants. Consequently, Descartes would refrain from publishing elements of his science and philosophy for fear of the Inquisition, and yet would readily settle in Protestant countries, where academics and theologians would viciously attack his work in part because they knew he was a Catholic.
Rene Descartes was baptized a Catholic in Saint George's Chapel in La Haye, a twelfth-century Norman church, on April 3, 1596. His baptismal certificate reads:
This day was baptized Rene, son of the noble man Joachym Descartes, councillor of the King and his Parliament of Brittany, and of damsel Jeanne Brochard. His godparents, noble Michel Ferrand, councillor of the King, lieutenant general of Chatellerault, and noble Rene Brochard, councillor of the King, judge magistrate at Poitiers, and dame Jeanne Proust, wife of monsieur Sain, controller of weights and measures for the King at Chatellerault.
[signed]
Ferrand Jehanne Proust Rene Brochard
Michel Ferrand, Rene Descartes' godfather, was his great-uncle— Joachim Descartes' uncle on his mother's side. Rene Brochard was the baby's grandfather, Jeanne Brochard's father. Jeanne's mother, Rene Descartes' grandmother, was Jeanne Sain. Her brother's wife was Jeanne (Jehanne) Proust.
The name La Haye comes from the French word haie, meaning hedge. Originally the town was named Haia, and in the eleventh century, as the language evolved, the spelling was changed to Haya. In Descartes' time it was called La Haye-en-Touraine. In 1802, the town's name was changed to La Haye-Descartes, in honor of the philosopher, and in 1967, “La Haye” was altogether dropped and the town is now known as Descartes.
There was once a castle in the area, and the wealthiest and most powerful citizens of La Haye lived in it. As the feudal system disintegrated, the castle was abandoned and the people moved down to the town, where they could live more comfortably. But life in this area remained difficult. People suffered both from wars and from disease. The plague ravaged La Haye and its surroundings several times in the late sixteenth and early seventeenth centuries. In 1607, the town was placed under quarantine after a recurrence of the plague killed many people in the area.
In early times, the hedges denoted by the French name Haia (or Haya or Haie) stood for thorny hedges that were planted by the townspeople in an effort to defend themselves and their property from marauding bands of brigands and highwaymen that pillaged and looted the countryside. But as times improved after the duke of Anjou took control of the area in September 1596—six months after the birth of Rene Descartes—the hedges implied by the name of the town came to mean hedges of beautiful gardens. To this day, this part of France is known for its exquisite gardens and areas of great natural beauty.
Late in life, just before he left on his final journey to Stockholm, Descartes wrote to his dearest friend, Princess Elizabeth: “A man who was born in the gardens of Touraine, shouldn't he avoid going to live in the land of the bears, between rocks and ice?” Descartes may well have been thinking of the garden of his own childhood home, his grandmother's house in La Haye, when he wrote these words to Elizabeth. Descartes' childhood home is an attractive two-story country house with four large rooms, although it is not nearly as impressive as the family mansion in Chatellerault. But it is surrounded by an exuberant garden, now restored to its original state, with flowers under the generous canopy of graceful trees. One can imagine the young boy enjoying many hours of undisturbed thinking and playing in this tranquil garden.
A year after Rene was born, shortly after giving birth to her fourth child, Jeanne Brochard died. The newborn survived for three more days, and then died too. Some of Descartes' biographers ha
ve written that Rene's personality was deeply affected by the loss of his mother, and have even speculated that the young boy blamed himself for her death because he did not quite understand—the event having taken place so close to his own birth—that she died sometime after giving birth to her next child.
After the death of his wife, Joachim remarried. He took a Breton woman named Anne Morin as his wife, and with her had another son and another daughter (and two other babies who died in infancy). They bought a house in Rennes, where Rene's older sister joined them in 1610, and where she got married in 1613 to a local man. Until then, Rene and his older brother and sister were raised by a governess. Rene Descartes was extremely attached to his governess, who was a devout Catholic. She lived to old age, and Descartes specified in his will that she was to receive a significant amount of money annually for her support.
As a child, Rene became known as the young philosopher of the family because he had a great curiosity about the world, always wanting to know why things were the way they were. The child grew up in the natural environment of farming and hunting and strolling in the woods. Throughout his life he would make references to the bucolic land of his birth and its natural rhythms. In letters to friends, and in published works, he would describe his childhood memories: the smell of the earth after a rainstorm; the trees at different seasons of the year; the process of fermentation of hay, and the making of new wine; the churning of butter from fresh milk; and the feel of the dust rising up from the earth as it was being plowed. Perhaps it was this early closeness to nature that kindled his interest in physics and mathematics as means for understanding nature and unraveling her secrets.
Descartes's Secret Notebook Page 2
