by remaining well hidden required a lot of dissimulation.”
He arrived with little furniture and few books, apart from his Bible. But once resettled, Descartes set a new and grandiose goal for himself. “Rather than explaining any one phenomenon by itself,” he wrote to Mersenne, “I have resolved to explain all the phenomena of nature, that is to say all of physics. I like my present plan better than any other I have ever had, for I think I have found a way of unfolding all my thoughts which some will find satisfying and which others will have no cause to disagree.” At the same time, he had begun to think about how to establish the existence of God and the immortality of the soul. In another letter to Mersenne, he wrote that he had “found a way of proving metaphysical truths that is more evident than the truths of geometry”—a claim almost as startling as his ambition to explain all the phenomena of nature.
From the start, Descartes ran into difficulties. He titled one part of his projected treatise The World (or, in French, Le Monde) and another part Treatise on Man. But it was not clear how to turn the findings of specific inquiries—about optics, meteorology, and the behavior of light rays—into the promised general explanation of nature. Nor was it clear how to organize and structure a treatise that would present solutions to both physical and long-standing metaphysical questions about the soul and intellect. He hoped to explain in sequence inanimate nature, animate nature, and mind.
In these years, he studied anatomy and physiology. He also busied himself by designing a new machine to cut lenses and also became fascinated with “automatons,” machines that seemed to move spontaneously—for example, clocks and water pumps. For the purposes of analysis, he proposed treating the human being as “nothing but a statue or machine made of earth.” In 1632, he wrote to Mersenne that he had become “caught up in the heavens. I have discovered their nature and the nature of the stars we see there and many other things which a few years ago I would not even have dared to hope to discover; and now I have become so rash as to seek the cause of the position of every fixed star.” The tone of his letters vacillated between elation at fresh discoveries and despair that his increasingly ambitious project could ever be completed.
Then disaster struck. “I had intended to send you Le Monde as a New Year gift,” Descartes wrote Mersenne in November 1633, “but in the meantime I tried to find out in Leiden and Amsterdam whether Galileo’s World System was available … I was told that it had indeed been published, but that all copies had been burned at Rome, and that Galileo had been convicted and fined. I was so surprised by this that I nearly burned all my papers, or at least let no one see them.”
He considered revising Le Monde in an effort to avoid offending the censors but rejected the idea, since Galileo’s teaching was “such an integral part of my treatise that I couldn’t remove it without making the whole work defective. But for all that, I wouldn’t want to publish a discourse which had a single word that the Church disapproved of; so I prefer to suppress it rather than publish it in a mutilated form.”
The vehemence of Descartes’s reaction is revealing. The Netherlands was beyond the reach of papal authority, and France itself had no Inquisition. Descartes could probably have published and distributed Le Monde in Amsterdam and Paris without incident, given the help of highly placed Catholic friends like Mersenne.
But his doubts and suspicions could not be assuaged. And Descartes was not interested in picking a fight with the Vatican. “I desire to live in peace,” he explained to Mersenne in April 1634, “and to continue the life I have begun under the motto ‘to live well you must live unseen.’ And so I am more happy to be delivered from the fear of my work’s making unwanted acquaintances than I am unhappy at having lost the time and trouble which I spent on its composition.”
Unfortunately, Descartes came under religious censure once again, this time because of his personal conduct. In August 1635, he appeared in a church at Deventer to acknowledge that he was the father of the girl being baptized. She was named Francine and had been born to Helene Jans, a maid in the house in Amsterdam