The condition of the people in the besieged city was now desperate. They had to resort to eating cats, dogs, and rats. Finally, having exhausted even this source of nourishment, some tried to eat the leather of belts and boots. Thirteen months after the siege began, in October 1628, the city surrendered to the French forces. Of the roughly twenty thousand inhabitants of La Rochelle before the siege began, only six thousand starving souls remained, barely alive, as the French forces stormed in. Still, some continued to fight as valiantly as they could, but they were no match for the well-fed French troops with their guns and ample ammunition.
After their last defeat, the Huguenots dispersed throughout Europe, moving to more tolerant countries. Some eventually came to the United States and founded the city of New Rochelle, New York.
Descartes entered La Rochelle with the king's forces the day the city fell to the French army, October 27, 1628. He was there to see the gloomy corteges—carriages laden with dead bodies were being pulled through the streets—and he saw the dying being given their last sacraments. This last battle, in which the French were fighting against their own starving Huguenot citizens, was an especially gory one. According to Baillet, “There has never been a worse spectacle since the fall of Jerusalem,” the destruction of Jerusalem by the Romans in A.D. 70. Once he had seen enough, Descartes returned to Paris. He arrived in the French capital again on an auspicious day for him: Saint Martin's Eve, November 10.
Why would Descartes come to the site of such a dreadful siege, one in which so many people died of starvation or by the sword? Descartes was not an evil man, and neither did he harbor anti-Protestant feelings, as evidenced by the fact that he first enlisted as volunteer in the army of Prince Maurice, who led a Protestant army in 1619. But Descartes had always been attracted to military order and structure. He had been trained as a young child, starting at the age of eleven, by the Jesuits, who were run as a semimilitary Christian order. At the College of La Fleche Descartes was introduced to almost military-style discipline, order, and uniforms. It appears that the structure—both architectural and behavioral—of a militarylike place such as La Fleche appealed to him. Additionally, Descartes always sought adventure and travel, and the military offered him both. Oddly, he could think clearly while war raged around him.
In the seventeenth century, war was waged in a well-ordered manner, similar to the way military parades are conducted today (which is perhaps the last vestige of the way armies behaved in the olden days). Soldiers on each side faced their enemy while arrayed in perfect rows, shooting at the enemy in unison. Modern warfare is completely different, and emphasizes camouflage, hiding, and an apparent lack of order, to prevent the enemy from exploiting any structure. Randomness is a key element in modern warfare, which stresses surprise and agility and unpredictable movements. The perfect order inherent in warfare in the 1600s seemed to attract Descartes' interest and appreciation. He is reported to have observed maneuvers and fighting, deriving from them a sense of harmony and symmetry. Descartes was interested in the trajectories of projectiles through the air; he was researching the fall of objects under the force of gravity. This research would inescapably lead him to the forbidden heliocentric theory of Copernicus.
Trajectories and military maneuvers and the construction of a unique dike to block off the entrance to La Rochelle harbor were strong motivations for Descartes to come to the coast of his ancestral Poitou to see for himself what was happening. And finally, Descartes was a man who always wanted to be at the right place at the right time. He was there when the emperor was crowned in Frankfurt, and he was in Venice to see the wedding of the city with the sea, and now he was in La Rochelle, where history (gory, to be sure) was being made. Descartes wanted to learn as much as he could about life, and the siege of La Rochelle was one such lesson.
Chapter 12
The Move to Holland and the Ghost of Galileo
DESCARTES RETURNED TO PARIS AT the end of October 1628, but soon left for Middelburg to visit Beeckman. He was returning to his mentor—the man who first got him interested in mathematics and started him on his way to pursuing a career as a mathematician and scientist. Descartes did not find his friend in Middelburg, and continued on to Dordrecht, where the two friends finally met each other at Beeckman's school.
Descartes shared with Beeckman his early attempts at unifying geometry with algebra. According to Beeckman's journal, Descartes was never able to meet anyone, in all his travels in Europe, who could understand his ideas about mathematics as well as Beeckman did. The two men discussed Descartes' novel methods in geometry and algebra, as well as music: chords and instruments and the transmission of sound. They also talked about the nature of light, and about gravity and other mysteries of physics. It seemed that the bond that united them—a love of learning and a belief in the power of mathematics—was stronger than ever. Descartes spent a few days with his friend, and then left. But they continued their regular communication through letters.
Shortly afterward, at the very end of 1628, Descartes suddenly moved to Holland. The reasons for this relocation have never been well understood. The move was permanent in the sense that Descartes would stay in Holland for the next two decades, and when he did leave that country, it would be to go to Sweden, not back to France. The move seems odd since Descartes was a Catholic and Holland was mostly Protestant. In his Discourse on the Method, published eight years later, Descartes said that he had moved to Holland because of a desire to distance himself from all the places at which he was known, and to live in a country in which a thriving, active population enjoyed the fruits of peace.
Holland also had more liberal printing laws than did France and other European countries, and this factor may have contributed to Descartes' decision to move, since he was hoping to publish some of his works. But Descartes' move may also have been motivated by a gnawing fear. His work had been moving in a dangerous direction—toward the Copernican theory of the universe—and Descartes worried that his discoveries in physics could be seen as contrary to the doctrines of the Catholic Church. It has been conjectured by the French scholar Gustave Cohen that the rumors, prevalent in Paris in the years 1623 to 1629, of a link between Descartes and the Rosicrucians had also contributed to his decision to leave France.
As time would prove, Descartes' move to Holland was a serious mistake. For there, he would suffer much more from Dutch theologians than he ever would have from Catholics. But perhaps his personality was changing as well. Descartes was becoming increasingly secretive.
When Descartes decided to leave France, Mersenne was disappointed and tried to dissuade him from leaving. But Descartes left despite all his efforts. He would spend the next twenty years wandering throughout Holland, carrying out a correspondence with European intellectuals—mostly through Mersenne, with whom he continued to discuss mathematical and philosophical problems. While Descartes was traveling through Holland, living for a few months or years in a given location, and then abruptly leaving for another town or village, he often did not give his true address to anyone but Mersenne. If he was staying in a town, he would dateline his letters from a neighboring town or large city. Since only Marin Mersenne knew exactly where Descartes was at any given time, all correspondence to Descartes from others had to go through the Minim friar. It seems that Descartes was hiding from someone or something.
Shortly after the move to Holland, Descartes experienced the first of the several conflicts that would come to characterize this period in his life.
It seems that Beeckman had also been experiencing a transformation through his interactions with Descartes. He developed a burning ambition to establish himself as a leading scientist, and perhaps even to compete with his brilliant friend. Early on in their relationship, on April 23, 1619, Descartes had written Beeckman saying that “if by chance something shall come out of me that would not be viewed with contempt, you may by all rights declare it as your own.” But this was, perhaps, a manifestation of Descartes' extreme politeness and
self-effacing nature as well as gratitude to a friend, rather than an invitation to Beeckman to claim credit for Descartes' achievements. At any rate, now Beeckman did claim such credit.
Soon after he last saw Descartes, Beeckman began his own correspondence with Marin Mersenne in Paris. Perhaps Descartes had facilitated the connection between the two men. The correspondence with Mersenne—the central figure in European mathematics and physical science in the century, the man who acted as a clearinghouse for all scientific work on the continent—was motivated by Beeckman's desire to show off his knowledge. Beeckman claimed to Mersenne, and through him to others, that it was he who had given Descartes many of his important ideas. Beeckman began to believe that he was the initiator of mathematical physics, and that Descartes was simply another person who could understand this new science, not its inventor.
Mersenne visited Beeckman in Holland, and continued on to pay a visit to Descartes. From Mersenne, Descartes found out about Beeckman's boastful claims of being the source of Descartes' knowledge—and he was deeply offended. Descartes immediately wrote to Mersenne:
I am very much obliged to you for calling to my attention the ingratitude of my friend. I think that the honor I had given him by writing to him has dazzled him and he thought that you might have a better opinion of him if he told you that he had been my master ten years ago. But he is completely mistaken, for what glory can there be in having taught a man who knows very little and freely admits it as I do? I will not mention any of this to him, since this is what you wish, but I would have much with which to make him ashamed, especially if I had his letter.
But Descartes was not assuaged by writing this letter to Mersenne. He wrote to Beeckman at the end of 1629, demanding that he return to him some of his papers, and severing all ties with his Dutch friend. In the middle of 1630, Mersenne visited Beeckman, and the latter showed him his journal, which he believed proved that he had, indeed, contributed to works by Descartes and that Descartes had not made all the discoveries he claimed without his help. When Descartes then received a letter from Beeckman telling him that he had shown his journal to Mersenne, proving his point, Descartes became even more angry than he had been until then. Descartes then wrote to Beeckman: “Now that I know that you are more interested in silly boasting than in true friendship and truth, let me tell you some things…. Undoubtedly, you were led to err by the politeness of our French language, when, be it in conversation, be it by letter, I have affirmed that I had learned many things from you.”
But Beeckman persisted in his claims to the intellectuals of his day that it was he who had taught Descartes mathematics and physics and music theory, and that Descartes' ideas all originated in conversations with him. He wrote to Descartes, repeating these assertions. Apparently, Beeckman believed his own priority strongly enough to write it in his journal. Among other things, Beeckman wrote in the journal in Latin: “Physiti mathematid paucissimi,” or, “Rare are the physicists-mathematicians.” But Descartes wrote to him, saying that “I have learned nothing from your imaginary physics, which you describe by the name mathematico-physics.”
On October 17, 1630, the final rupture came. Descartes lost all patience with Beeckman and his claims on Descartes' glory. That day, he wrote him a letter that was devoid of his habitual politeness and finesse. Descartes denounced what he called Beeckman's “stupidity and ignorance.” He added: “Now I recognize by all the evidence, from your last letter, that you have sinned not by malice but by insanity.” Descartes in sisted that he had never learned anything from Beeckman, except perhaps the smallest things about nature, such as “of ants and small worms.” Perhaps surprisingly, the two men still continued to write sporadically to each other, and they even met. But their friendship was never the same again—it lost most of its warmth and enthusiasm.
In October 1629, Descartes started to work on a book on physics and metaphysics, which he called Le Monde (“The World”). But then in 1633, four years into this ambitious project and just when the treatise was ready to be published, Descartes heard about the trial of Galileo. Descartes' intellectual progress through life took him from pure mathematics to metaphysics, and from metaphysics to physics and cosmology. But the news about Galileo constituted a blow of unparalleled magnitude.
Starting a decade earlier, Descartes sought to apply the principles he had developed in algebra and geometry to address problems of the physical world. Descartes took the ideas of his predecessors and easily verified many of them—and disputed others—using his keen geometrical analysis. He formed a view of the universe that was squarely in agreement with the Copernican theory that the sun is the center of our solar system and the planets, including Earth, orbit the sun. Everything in Descartes' work in physics—his study of falling objects and gravity, and his observations of trajectories of cannonballs and bullets—agreed with this theory.
Descartes' physics was what we might call mathematical physics or theoretical physics. He deduced the laws of nature from first principles derived from mathematics. It was an intellectual exercise through which mathematics gave him answers about the physical world: the laws of falling bodies, the rotation of the earth, and the orbits of the planets around the sun. Le Monde, dedicated to Descartes' friend Mersenne in appreciation for all that he had done to promote the growth of science, mathematics, and philosophy, was his scientific description of the creation and the workings of the world—a revision of the book of Genesis in an attempt to reconcile science with religious belief. But just before the book was to be published, in November 1633, Descartes received the news about Galileo and he immediately canceled the publication of his book. He even “almost resolved to burn all my papers or at least not to let any person see them,” as he later described his resolution.
History would show that Descartes was less vulnerable to the dangers that plagued Galileo than he might have thought. First, Descartes never baited the Inquisition the way Galileo had done in his writings (in which the church was represented by Simplicius, the simpleton). Second, Descartes lived in a country, Holland, that was less under the influence of Rome than was Galileo's Tuscany. And third, Descartes had very powerful allies. In 1637, Descartes' friend Mersenne would request and obtain from King Louis XIII the privilege of publishing without hindrance for “our beloved Descartes.” But that would happen some years in the future, and when it did happen, it did not change Descartes' course of action. Descartes remained resolute not to publish his treatise on physics.
Descartes continued to study physics, but he refrained from publishing conclusions that could be objectionable to the church, and concentrated on a different form of physics. The shock of the trial of Galileo caused Descartes to move from theoretical physics—physics based on the use of mathematics—to experimental physics, that is, physics based on experiments in the real world, without a theoretical basis that might lead to conclusions that could enrage the powerful Inquisition.
In his first and most important published book, Discourse on the Method, which appeared in 1637, Descartes publicly explained his dilemma of Le Monde. Right after the beginning of the fifth part of his Discourse, Descartes wrote the following.
I would now need to speak about several questions that are considered controversial by the savants, with whom I do not wish to get embroiled; I think it would be better that I abstain from doing so, and that I say only in general terms what these issues are, and leave it to the wisest to determine whether it should be useful for the public to be informed about these issues more specifically. … I have taken notice of certain laws that God had thus established in nature, and of which he had imprinted such notions in our souls, that after enough reflection about them, we would not doubt that they are exactly observed in everything that is or is done in the world. Furthermore, considering the consequences of these laws, it seems that I have discovered many truths that are more useful and more important than the ones I had learned at first, or hoped to learn.
Descartes' Le Monde was published only
in 1664—fourteen years after his death. The passage above refers to the material in chapter VII of Le Monde, in which Descartes described the three principal laws of nature governing the movements of bodies. These laws are speed, direction, and communication of movement in space. According to Descartes, these rules are founded on the immutability of divine law. Descartes believed that God created the laws of nature and made them known to man. He thus believed that the rotation of the earth and the revolution of the earth and the planets around the sun were direct consequences of the laws of conservation of momentum (to use modern terminology) and that they were self-evident.
But because of his worries about the Inquisition, Descartes could only hint at these ideas. He had to use coded or disguised language, and to keep most of his scientific deduction secret. Because of the fear of upsetting the church by lending theoretical support to the Copernican theory, Descartes was robbed of recognition of his role in discovering the laws of motion and of the conservation of momentum. Apparently, Descartes' genius was so profound that he was able to deduce the rotation of the earth and the motion of the planets by deriving first principles of physics, and then applying these rules to the solar system. He attributed the resulting laws of nature to divine decree. The deepest insight we can gain about Descartes' process of reasoning and physical analysis—and how it related to his religion and view of God in the universe—which were the key elements in the retracted Le Monde, can be gleaned from an important letter Descartes wrote to Mersenne on April 15, 1630. An excerpt follows.
Descartes's Secret Notebook Page 12