Descartes and the
Delirious Origins of Modern Science

July 18, 2023

There was a time when science was done by dropping objects from tall buildings, or mixing chemicals together and journaling about what happened. There weren't a lot of formulas or statistical models so much as there were people tinkering with things and making observations. Mathematics is the foundation of modern science though, the theories of quantum physics and general relativity are so intertwined with their mathematical representations that they can't even be described without them. An electron is neither a wave nor a particle, it's a mathematical object called a wavefunction.

But the idea that the secret truths of the universe could be described with equations is not self-evident. Before you were taught it was so, could you imagine that the richness and complexity of reality could be described by numbers? And to think it could all be captured on a single page by a handful of formulas should seem absurd.

This absurd idea that would completely transform science came from a series of three delirious dreams that a young 20-year-old René Descartes had in 1619, many years before he would become the father of rationalism and one of the most famous philosophers of history.

Below is a translated recounting of his three dreams from an early biographer of Descartes [1]. In it, Descartes describes seeing phantoms, hearing thunderclaps, and having an enigmatic chat with a stranger. Two books appear before him, a dictionary and a book of poems, and a new kind of universal mathematics is revealed by a "Spirit of Truth." [2] It is the bizarre origin story for our modern philosophy of science.

Descartes' Three Dreams

FIRST DREAM. "He informs us [in margin: CART. OLYMP. init. Ms.] that, on the tenth of November 1619, having gone to bed completely filled with enthusiasm and wholly occupied with the thought of having discovered that very day the foundations of the miraculous science, he had three consecutive dreams in a single night that he imagined could only have come from on high. After having gone to sleep, his imagination was struck by the representation of certain phantoms which presented themselves to him, and which frightened him in such a way that, believing that he was walking up the street [in margin: CaRT. OLyMP.], he was obliged to fall back onto the left side in order to be able to advance to the place where he wished to go, because he felt a great feebleness on the right side, which he could not sustain. Being ashamed of walking in this manner, he made an effort to straighten up; but he felt a violent wind which, carrying him off in a kind of vortex, caused him to spin three or four times on the left foot. This was still not what frightened him. The difficulty which he had in dragging himself along made him believe that he would fall at every step until, perceiving a college open on his way, he entered within in order to find a retreat there, and a remedy for his trouble. He tried to gain the church of the college, where his first thought was to go to make his prayers; but perceiving that he had passed a man of his acquaintance without greeting him, he wished to retrace his steps to be civil to him, and was repelled with violence by the wind which blew against the church. At the same time he saw another person in the middle of the college courtyard who called him by his name in civil and obliging terms, and told him that if he wished to go find Monsieur N., he had something to give him. M. Descartes imagined that this was a melon which had been brought from some foreign country. But what surprised him more was to see that those who gathered with this person, around him in order to converse, were erect and firm on their feet, although he remained bent and wavering on the same terrain, and that the wind which he thought would upset him several times had greatly diminished. He awoke on this imagination, and felt at the time an actual pain, which made him fear that this was the operation of some evil spirit who had wanted to seduce him. He immediately turned over on his right side; for it was on the left that he had gone to sleep and had had the dream. He prayed to God to ask to be guaranteed from the bad effect of his dream, and to be preserved from all the misfortunes which could threaten him as punishment for his sins, which he recognized could be grave enough to draw down the thunders of heaven [foudres du ciel] on his head: although he had led up till then a life sufficiently irreproachable in the eyes of men."

SECOND DREAM. "In this situation he went back to sleep after an interval of almost two hours in various thoughts on the goods and evils of this world. A new dream immediately occurred to him, in which he believed he heard a sharp and piercing sound that he took for a clap of thunder [un coup de tonnerre]. The terror it caused awoke him that very moment; and having opened his eyes he saw many sparks [étincelles] of fire scattered about the room. The thing had often occurred before, at other times; and it was not especially extraordinary, upon waking in the middle of the night, for his eyes to be so besparkled [étincelants] that he saw confusedly the objects closest to him. But on this latter occasion he sought recourse to reasons taken from philosophy; and he drew therefrom conclusions favorable to his mind, after having ob-served, upon opening and then closing his eyes alternately, the quality of the appearances [espèces] represented to him. Thus his terror dissipated, and he went back to sleep in a very great calm."

THIRD DREAM. "A moment after, he had a third dream, which had nothing terrifying, as had the first two. In this latter one, he found a book on the table, without knowing who had put it there. He opened it, and seeing that it was a Dictionary was delighted with it, in the expectation that it could be most useful to him. In the same instant he discovered another book at hand, which was not less new to him, not knowing where it had come from. He found that it was a collection of poems by different authors, entitled Corpus poetarum etc. [in margin: divided into five books, printed at Lyons and at Geneva, etc.]. He had the curiosity to wish to read something: and upon opening the book he fell on the verse 'What way of life ought I to follow? [Quodvitae sectabor iter?]. At the same moment he saw a man he did not know, but who presented to him a piece of verse, beginning with 'Yes and No' [Est et Non], and praised it to him as an excellent piece. M. Descartes told him that he knew which it was, and that this piece was among the Idyllia of Ausonius, which were found in the large collection of poets on his table. He wished to show it himself to this man, and began to leaf through the volume, of which he claimed to know the order and arrangement perfectly. While he was looking for the place, the man asked him where he had got the book, and M. Descartes replied to him that he could not say how he had; but that a moment previously he had handled still another, which had just disappeared, without knowing who had brought it to him or who had taken it away from him. He had not finished when he again saw the book appear at the other end of the table. But he found that this Dictionary was no longer complete, as he had seen it the first time. Meanwhile he came to the poems of Ausonius in the collection of poets that he was leafing through; and not being able to find the piece which began with Est et Non, he said to the man that he knew one by the same poet still more beautiful than that one, and that it began with Quod vitae sectabor iter? The person requested him to show it to him, and M. Descartes set about finding it, when he chanced on several small engraved portraits: which made him say that this book was extremely beautiful, but that it was not of the same edition as that which he knew. He was at this point when the books and the man disappeared and effaced themselves from his imagination, without, however, awakening him. What is remarkable is that, doubting whether what he had just seen was dream or vision, he not only decided, while sleeping, that it was a dream, but he even made the interpretation of it before sleep left him. He judged that the Dictionary meant no other thing but all the sciences gathered together; and the collection of poems, entitled Corpus poetarum, indicated in particular, and in a more distinct manner, philosophy and wisdom joined together. For he did not believe that one should be greatly astonished to see that the poets, even those who only play the fool, were full of sentences more grave, more sensible, and better expressed than those which are found in the writings of the philosophers. He attributed this marvel to the divinity of enthusiasm and to the force of imagination, which thrusts out the seeds of wisdom (which are found in the mind [l'esprit] of all men, like sparks of fire in stones) with much more facility, and even much more brilliance, than reason can do in the philosophers. M. Descartes, continuing to interpret his dream in his sleep, considered that the piece of verse on the uncertainty of the kind of life one ought to choose, which begins by Quod vitae sec-tabor iter?, indicated the good counsel of a wise person, or even moral theology.

"Thereupon, doubting whether he dreamed or meditated, he awoke without emotion, and continued, with open eyes, the interpretation of his dream on the same idea. By the poets gathered in the collection he understood revelation and enthusiasm, of which he did not despair to see himself favored. By the piece of verse Est et Non, which is the Yes and No of Pythagoras [in margin: nai kai ou], he understood truth and falsity in the human knowledges [connaissances] and the profane sciences. Seeing that the application of all these things succeeded so well to his taste, he was so bold as to persuade himself that it was the Spirit of Truth who had sought to open to him the treasures of all the sciences by this dream. And as there remained nothing more to explain but the small engraved portraits that he had found in the second book, he searched no more for the explanation after the visit an Italian painter made to him the next day."