Is God a Mathematician_ - Mario Livio [42]
After La Flèche, Descartes graduated from the University of Poitiers as a lawyer, but he never actually practiced law. Restless and eager to see the world, Descartes decided to join the army of Prince Maurice of Orange, which was then stationed at Breda in the United Provinces (The Netherlands). An accidental encounter in Breda was to become very significant in Descartes’ intellectual development. According to the traditional story, while wandering in the streets, he suddenly saw a billboard that appeared to present a challenging problem in mathematics. Descartes asked the first passer-by to translate the text for him from Dutch into either Latin or French. A few hours later, Descartes succeeded in solving the problem, thus convincing himself that he really had an aptitude for mathematics. The translator turned out to be none other than the Dutch mathematician and scientist Isaac Beeckman (1588–1637), whose influence on Descartes’ physico-mathematical investigations continued for years. The next nine years saw Descartes alternating between the hurly-burly of Paris and service in the military corps of several armies. In a Europe in the throes of religious and political struggle and the commencement of the Thirty Years’ War, it was relatively easy for Descartes to find battles or marching battalions to join, be it in Prague, Germany, or Transylvania. Nevertheless, throughout this period he continued, as he put it, “over head and ears in the study of mathematics.”
Figure 21
On November 10, 1619, Descartes experienced three dreams that not only had a dramatic effect on the rest of his life, but which also marked perhaps the beginning of the modern world. When later describing the event, Descartes says in one of his notes: “I was filled with enthusiasm and discovered the foundations of a wonderful science.” What were these influential dreams about?
Actually, two were nightmares. In the first dream, Descartes found himself caught in a turbulent whirlwind that revolved him violently on his left heel. He was also terrified by an endless sensation of falling down at each step. An old man appeared and attempted to present him with a melon from a foreign land. The second dream was yet another vision of horror. He was trapped in a room with ominous thunderclaps and sparks flying all around. In sharp contrast to the first two, the third dream was a picture of calm and meditation. As his eyes scanned the room, Descartes saw books appearing and disappearing on a table. They included an anthology of poems entitled Corpus Poetarum and an encyclopedia. He opened the anthology at random and caught a glimpse of the opening line of a poem by the fourth century Roman poet Ausonius. It read: “Quod vitae sectabor iter?” (“What road shall I pursue in life?”). A man miraculously appeared out of thin air and cited another verse: “Est et non” (“Yes and no” or “It is and it is not”). Descartes wanted to show him the Ausonius verse, but the entire vision disappeared into nothingness.
As is usually the case with dreams, their significance lies not so much in their actual content, which is often perplexing and bizarre, but in the interpretation the dreamer chooses to give them. In Descartes’ case, the effect of these three enigmatic dreams was astounding. He took the encyclopedia to signify the collective scientific knowledge and the anthology of poetry to portray philosophy, revelation, and enthusiasm. The “Yes and no”—the famous opposites of Pythagoras—he understood as representing truth and falsehood. (Not surprisingly, some psychoanalytical interpretations suggested sexual connotations in relation to the melon.) Descartes was absolutely convinced that the dreams pointed him in the direction of the unification of the whole of human knowledge by the means of reason. He resigned from the army in 1621 but continued to travel and study mathematics for the next five years. All of those who met Descartes during that time, including