Descartes

by A. C. Grayling

  Descartes' choice of a place to go, given the necessity of leaving France, was not a hard one. The unsettled state of the warring German lands, the heat and disorganisation of Italy, and by contrast the flourishing, wealthy, populous and relatively liberal atmosphere of the Netherlands in its seventeenth-century glory, settled the matter for him by itself. Moreover, he knew the Netherlands already from his Breda period, could speak the language to some extent, and had his friend Beeckman there. A yet further inducement was that, as the country had grown rich following its post-Reformation liberation from Spain, many schools and universities had sprung up in its rapidly expanding towns, and in them Descartes saw an opportunity for furthering his work.

  Long before this time he had made up his mind to try to replace Aristotelian orthodoxy in matters of science and philosophy with his own views, and that meant getting them accepted into the curricula of academies. His great ambition was to have the Jesuits adopt them, but as a step towards that end he wanted to persuade some of the new Dutch schools to adopt them first. When he arrived in the Netherlands it was with the aim of writing out his ideas in a treatise, and promoting its acceptance as a textbook. The first four Dutch years were devoted to that task.

  For our purposes, a happy feature of Descartes' long sojourn in the Netherlands is that because he was separated from Mersenne and others who mattered to him, he was obliged to write letters, and accordingly wrote many. In the second of the two decades— the 1640s—his fame brought him to the attention of two socially distinguished women: Princess Elizabeth, daughter of the ill-fated Winter King and Queen of Bohemia, and Queen Christina of Sweden. Both, but especially the first, prompted him to write about subjects he might not otherwise have investigated, which added to his oeuvre and yet further to his celebrity. It is an irony that he should have had such a warm and consequential epistolary friendship with the Princess Elizabeth of Bohemia, given that he had been pitted against her parents' side of the argument at the opening of the Thirty Years War, nearly a quarter of a century before their correspondence began.

  In his first months in the Netherlands, probably starting in late 1628, Descartes was in Dordrecht with Beeckman, the only person, so Descartes told him, with whom he could discuss science properly. Their friendship immediately renewed itself, but only temporarily; it was to receive a serious setback some months later. From Dordrecht Descartes went to Amsterdam, staying long enough to begin an acquaintance with Henry Reneri, a scholar who was later to be important to the dissemination of his ideas. These were just visits; he had not yet reached the place where he wanted to settle for the time being, which was Franeker, a small town (it is so still) in Friesland in the north of the Netherlands. Franeker 'was at that time an important regional centre for education, having had its university since 1585 (it lasted until 1811)—one of the Reformation institutions which sprang up, and in the 1630s were still springing up, all over that vigorous country.

  Descartes arrived in Franeker in the spring and registered at the university as "Rene Des Cartes, French philosopher" in an entry dated 16 April 1629.3 Registration was free and there was no religious test for entry, so this was an easy and attractive way for Descartes to make contact with people who might be intellectually stimulating. He attended the lectures of the university's professor of mathematics, Adrien Metius, author of a treatise on practical geometry and arithmetic, and brother of Jacques Metius, who had some claim to be one of the first improvers of the telescope. Descartes profited from the opportunity to widen his knowledge of astronomy and anatomy.

  Franeker was the home, for her first nineteen years, of an exceedingly brilliant girl called Anna Maria van Schurman, whose knowledge of the classical tongues had inspired admiration among the learned before she was a teenager, and who had been praised by such poets as Anna Roemers Visscher and Jacob Cats for her literary knowledge in Hebrew, Greek, Latin and French. Schurman and her widowed mother left Franeker for Utrecht only a year before Descartes' arrival. In 1635 Utrecht acquired its own university, and Schurman—still in her twenties—was invited to write the celebratory ode for its opening. She was also permitted to study there, closeted in solitude behind a screen with a grille. Henry Reneri was appointed to a professorship at Utrecht, and soon afterwards— for by that time Descartes had published some of his ideas in his Discourse on Method—began to teach Cartesian philosophy to its students, Schurman among them. At about that time Descartes and Schurman met; she was "the star of Utrecht" for a number of years, and published several of her works while there, including De ingenii mulieribus ad doctrinam, et meliores litteras aptitudine (On the aptitude of the female mind for science and letters). Their lives connected again indirectly in that both were patronised by Princess Elizabeth— in Schurman s case, when Elizabeth sheltered a primitive Christian sect Schurman joined in her later years (to the bitter disappointment of her many humanist admirers). But the personal acquaintance between Descartes and Schurman ceased as a result of their taking different sides in an acrimonious personal dispute that broke out between Descartes and the rector of Utrecht University, Gisbert Voetius, whom Schurman liked.

  The point of mentioning Anna Maria van Schurman is that it illustrates the importance attached to learning in the Netherlands at that time. For all its mercantile interests and emphatically bourgeois society, the Netherlands was then Europe's leading country for the arts and sciences. Elsewhere in Europe a prodigy like Anna Maria van Schurman might have gone unrecognised and uncelebrated— might indeed have been regarded with a certain repugnance as having proclivities unbecoming a girl (though acceptable in queens like Elizabeth of England or Christina of Sweden, or a princess like Elizabeth of Bohemia; royalty was granted license). But seventeenth-century Franeker was proud of Schurman, as was Utrecht. Into such an environment Descartes came in the spring of 1629, and he found it very congenial. The letters he wrote at this period show that he was thinking about metaphysics, in particular, the existence of God and the immortality of the soul, and about music—in particular, the effects of music on the mind; and most of all about optics and optical illusions, in particular the problem of how to make lenses that would be free of the aberrations which then afflicted all available lenses.

  In June Descartes wrote to Jean Ferrier in Paris inviting him to come to the Netherlands so that they could work together on a machine for cutting hyperbolic lenses, which Descartes had worked out would give a sharper focus than the spherical lenses everyone else produced.4 Ferrier was a gifted maker of scientific and optical instruments, and Descartes was convinced that with his designs and Ferrier's skills they could make lenses that would, as he said in a letter to Ferrier, give such clear magnification that they would be able "to see whether there are animals on the moon." His idea was that he and Ferrier would live and work together "like brothers," with Descartes bearing all costs.5

  Ferrier was at that very point being offered a job by no less a personage than Gaston, brother of King Louis XIII of France, which would involve living in apartments in the Louvre as one of its resident craftsmen. While waiting for this mouth-watering appointment to be confirmed Ferrier prevaricated, to the extent that Descartes eventually became irritated, and wrote him an angry letter. While still trying to persuade him to come, though, Descartes was cautious about revealing his whereabouts; he told Ferrier that he should travel to Dordrecht, where Beeckman would give him instructions about the next stage of his journey, and money for undertaking it. The secrecy cannot have added to the invitation's attractions.

  If Ferrier had joined Descartes in Franeker and they had worked on lenses together, the errors in Descartes' design might have become evident to him. As it was, decades later Robert Hooke of the Royal Society in London attempted to construct Descartes' hyperbolic-lens-making machine, and found—as he had predicted—that it would not work. But an examination of the correspondence between Descartes and Ferrier about the theory underlying the machine makes it clear that Descartes had discovered an important law in thinking about
hyperbolic lenses: the sine law of the refraction of light.

  Ferrier was not the only person Descartes quarrelled with, nor the most significant. Following the renewal of contact between Descartes and Beeckman, a major rift opened between them because of Descartes' occasional aptness for Luciferian pride. In a letter to Mersenne, Beeckman said that he had taught Descartes about harmony ("the sweetness of consonances" in music) when the two were collaborating ten years earlier. Mersenne told Descartes what Beeckman had said, and Descartes, taking this to be an imputation either of plagiarism on his part, or of Beeckman's priority in the discovery about harmony, grew very angry. "I am most obliged to you for informing me of my friend's ingratitude," he wrote to Mersenne. "I think I have dazzled him by bestowing on him the honour of writing to him, and he thought that you would think even better of him if he told you that he had been my teacher ten years ago. But he is utterly wrong."6

  Evidently, Mersenne had asked Descartes not to tell Beeckman that he, Mersenne, had passed on Beeckman's remarks, so at first Descartes said nothing about the matter to Beeckman—until Mersenne visited the Netherlands in 1630, and learned from reading Beeckman's journals the extent to which the young Descartes of 1619 had indeed been indebted to the Dutchman for both the manner and matter of a number of his early speculations. Although Descartes had so far said nothing, he had asked Beeckman for the return of his little Treatise on Music, and thereafter ceased to write to him. When Mersenne realised that Descartes had been more than a little unfair to Beeckman he taxed him with it, and Descartes exploded—against Beeckman. "Last year I took back my Music from you not because I needed it but because someone told me you'd spoken of it as if I had learned it from you," he wrote to him in a rage. "Now that I have established that you prefer stupid boasting to friendship and truth, I say to you in two words that even if you had indeed taught something to someone, it would be hateful of you to say so, and even more hateful if it were false. But it is worst of all when you have learned from the person yourself... I warn you not to show those who know me my letters to prove this because they know I am accustomed to learn even from ants and worms."7 When Beeckman wrote back in conciliatory terms suggesting that they meet to talk things over, Descartes replied in even more violent language. "You claim great praise for teaching me about the hyperbola. If I did not pity you for being sick I would certainly not be able to keep from laughing, because you don't even know what a hyperbola is." And then, "I'd never have suspected that your stupidity and self-ignorance is so great that you really believe I have learned more from you than I am accustomed to learn from other natural things . . . it is obvious to me from your letter that you sin not from malice but insanity."8

  It is instructive to be reminded of what Descartes had written to Beeckman as he travelled in Germany a decade before: "I shall honour you as the first mover of my studies and their first author. For you, truly, have roused me from idleness, and rewoken in me a science I had almost forgotten. You have brought me back again to serious endeavours, and have improved a mind that had been separated from them. If therefore I produce anything that is not contemptible, you have a right to claim it as yours."9 As Beeckman's journal shows, not only did he not claim anything of Descartes' as his own, but he was frankly generous about everything he learned from others, including his school pupils; and he even rejoiced in Galileo's published successes, despite having privately anticipated several of them in his own work.

  The episode does Descartes no personal credit. A reconciliation of sorts was effected, but the old cordiality had gone, and when Beeckman died a few years later Descartes showed little regret.10 The incident demonstrates how much his intellectual confidence had grown in the ten years since his previous sojourn in the Netherlands, and with it his conviction that he had much of value to offer. He was beginning work on an ambitious project—nothing less than a new system of the universe, a comprehensive natural philosophy which he confidently intended should replace Aristotelianism—and as all thinkers have done in modern times, particularly in mathematics and science, he was determined to get the credit for his discoveries by being acknowledged as the first to make them. That explains his rage at Beeckman, whom he unjustly suspected of trying to steal his thunder. It also, to add to the gracelessness of the incident, explains his refusal to acknowledge what Beeckman had indeed taught him.

  Doubtless Descartes chose Franeker as his place of resort because it combined a certain remoteness—located in Friesland, the Netherlands' north—with a university; but a few months' stay seems to have been enough to persuade him to move closer to the centre of things. In fact he went right to the centre, moving in October 1629 to Amsterdam. This gives the lie to previous biographers and commentators when they say that Descartes left France for the Netherlands to escape people and to enjoy the peace and quiet needed for his work; for Amsterdam in this rich and ebullient period of the Netherlands' history was scarcely a place of peace and quiet. It was one of the great cities of the world, populous, busy, a crossroads for trade and travel, the commercial capital of what was arguably the most successful international economy then in existence.11 Descartes lived in the city for considerable stretches over the next six years, starting in Kalverstraat before moving to the Dam (this latter the city's busiest thoroughfare, located right at the city's heart), and later to Westerkirkstraat.

  But his residence in Amsterdam was not continuous. In the summer of 1630 he went to Leiden, registering at the town's university as a student of mathematics on 27 June. The Album Studiosorum also gives his address: he lodged at the house of Cornells Heymeszoon van Dam, who lived with his wife and five children at the Verwelfde Voldersgracht. Whereas registration had been free at Franeker, Descartes had to pay at Leiden; the Album Studiosorum differentiated between those who attended with and without fee, and his name appeared among the former. The principal attraction for him at Leiden's university was the presence of the brilliant polymath Jacob Golius, who was not only professor of Arabic and author of a celebrated Arabic dictionary, but also professor of mathematics.12

  At the university Descartes renewed his acquaintance with Henry Reneri, and their association now blossomed into an important friendship. Reneri subsequently moved to Deventer to take up an appointment at the Ecole Illustre, and Descartes visited him there for long periods in 1632 and 1633. They discussed Descartes' views in detail, and Reneri read his unpublished manuscripts. In 1635 Reneri became professor at the newly founded university of Utrecht and began to lecture on Descartes' theories, the first significant step in the dissemination of Cartesian thought apart from personal correspondence.

  At Leiden, Descartes attended not only Golius's lectures on mathematics but also those on astronomy by Martin Hortensius. Given that he was engaged in writing about these subjects in his new "system of the world" it must have been a stimulus—even if he disagreed with what he heard—to his labours. But by far the most important event for Descartes in 1630 was his meeting with Constantijn Huygens, a large figure in the Netherlands' history, and a crucial patron and protector for Descartes thereafter.

  Constantijn Huygens was the same age as Descartes, but had already distinguished himself in the diplomatic service of his country on missions to Venice and London, and was the first secretary to the Prince of Orange in his office as Stadhouder of the United Provinces. In a long career (he died aged ninety in 1687) he served three princes of Orange in their office of Stadhouder: Prince Maurice, Prince Frederick-Henry, and Henry III. In addition to his government work he acquired distinction as a poet, was knowledgeable about the sciences, and was a patron of Rembrandt. His father had also been chief advisor to a Stadhouder, and his son Christiaan Huygens—aged just one when Descartes and Constantijn Huygens first met—was to acquire fame as a scientist, later becoming a Fellow of the Royal Society of London. Constantijn himself had been knighted by James I in 1622 for services which, also later performed by his son Christiaan, were not greatly different from those hypothesised here for Descartes: the t
ransmission of intelligence, and other secret help.

  Descartes said of Constantijn Huygens: "I could not believe that a single mind could occupy itself with so many things, and equip itself so well in all of them." This was high praise from one so jealous of his own abilities. Huygens recognised Descartes' qualities in return, and his support was unstinting. One of the earliest results of their acquaintanceship was that Huygens brother-in-law became Descartes' banker.

  This was a flourishing period for Descartes. He was happy; he wrote to his Paris friend, the writer Jean-Louis Guez de Balzac, "I sleep ten hours a night here, without a care to wake me." Amsterdam was a mere half-day's journey from Leiden, so in the late autumn of 1630 he moved back to the great city, and in the following spring again wrote to de Balzac, rejoicing in the anonymity of walking among crowds busy with their own affairs, a fascinated spectator of the life of a bustling entrepot. "There is no one here other than me who does not engage in commerce," he told de Balzac. "Each is so wrapped up in his own affairs that I could live here my whole life long without being noticed by anyone. I walk every day through the tumult of a great people with as much freedom and ease as you enjoy in your country paths; and I pay no more heed to the people I see than I would to the trees in your woods or the animals that live there. Even the noise of their doings does not disturb my reveries more than would the babbling of a stream. Reflecting on their activities gives me as much pleasure as you get from watching the peasants in your fields, because I see that everything they do enhances the place where I live, so that I shall want for nothing. You are given pleasure by seeing how your fruits and vines flourish, and you enjoy their abundance; that is how I feel when I see the ships coming into port here, bringing all the produce of the Indies and everything rare in Europe."13