Descartes, René (1596-1650)

Discourse on the Method

Leiden

1637

"Now a painter cannot represent all the different sides of a solid body equally well on his flat canvas, and so he chooses one of the principal ones, sets it facing the light, and shades the others so as to make them stand out only when viewed from the perspective of the chosen side. In just the same way, fearing that I could not put everything I had in mind into my discourse, I undertook merely to expound quite fully what I understood about light."

I endeavoured to explain the most important of these truths in a treatise which certain considerations prevent me from publishing, and I know of no better way to make them known than by summarizing its contents. My aim was to include in it everything I thought I knew about the nature of material things before I began to write it. Now a painter cannot represent all the different sides of a solid body equally well on his flat canvas, and so he chooses one of the principal ones, sets it facing the light, and shades the others so as to make them stand out only when viewed from the perspective of the chosen side. In just the same way, fearing that I could not put everything I had in mind into my discourse, I undertook merely to expound quite fully what I understood about light. Then, as the occasion arose, I added something about the sun and fixed stars, because almost all light comes from them; about the heavens, because they transmit light; about planets, comets and the earth, because they reflect light; about terrestrial bodies in particular, because they are either coloured or transparent or luminous; and finally about man, because he observes these bodies. But I did not want to bring these matters too much into the open, for I wished to be free to say what I thought about them without having either to follow or to refute the accepted opinions of the learned. So I decided to leave our world wholly for them to argue about, and to speak solely of what would happen in a new world. I therefore supposed that God now created, somewhere in imaginary spaces, enough matter to compose such a world; that he variously and randomly agitated the different parts of this matter so as to form a chaos as confused as any the poets could invent; and that he then did nothing but lend his regular concurrence to nature, leaving it to act according to the laws he established. First of all, then, I described this matter, trying to represent it so that there is absolutely nothing, I think, which is clearer and more intelligible, with the exception of what has just been said about God and the soul. In fact I expressly supposed that this matter lacked all those forms or qualities about which they dispute in the Schools, and in general that it had only those features the knowledge of which was so natural to our souls that we could not even pretend not to know them. Further, I showed what the laws of nature were, and without basing my arguments on any principle other than the infinite perfections of God, I tried to demonstrate all those laws about which we could have any doubt, and to show that they are such that, even if God created many worlds, there could not be any in which they failed to be observed. After this, I showed how, in consequence of these laws, the greater part of the matter of this chaos had to become disposed and arranged in a certain way, which made it resemble our heavens; and how, at the same time, some of its parts had to form an earth, some planets and comets, and others a sun and fixed stars. Here I dwelt upon the subject of light, explaining at some length the nature of the light that had to be present in the sun and the stars, how from there it travelled instantaneously across the immense distances of the heavens, and how it was reflected from the planets and comets to the earth. To this I added many points about the substance, position, motions and all the various qualities of these heavens and stars; and I thought I had thereby said enough to show that for anything observed in the heavens and stars of our world, something wholly similar had to appear, or at least could appear, in those of the world I was describing. From that I went on to speak of the earth in particular: how, although I had expressly supposed that God had put no gravity into the matter of which it was formed, still all its parts tended exactly towards its centre; how, there being water and air on its surface, the disposition of the heavens and heavenly bodies (chiefly the moon), had to cause an ebb and flow similar in all respects to that observed in our seas, as well as a current of both water and air from east to west like the one we observe between the tropics; how mountains, seas, springs and rivers could be formed naturally there, and how metals could appear in mines, plants grow in fields, and generally how all the bodies we call 'mixed' or 'composite' could come into being there. Among other things, I took pains to make everything belonging to the nature of fire very clearly understandable, because I know nothing else in the world, apart from the heavenly bodies, that produces light. Thus I made clear how it is formed and fuelled, how sometimes it possesses only heat without light, and sometimes light without heat; how it can produce different colours and various other qualities in different bodies; how it melts some bodies and hardens others; how it can consume almost all bodies, or turn them into ashes and smoke; and finally how it can, by the mere force of its action, form glass from these ashes - something I took particular pleasure in describing since it seems to me as wonderful a transmutation as any that takes place in nature.
(Part Five, p. 131-3)

Visual Arts::Painting Uncategorized::Object

Past Masters

Descartes, René. The Philosophical Writings of Descartes. Trans. John Cottingham, Robert Stoothof, and Dugald Murdoch. Cambridge: Cambridge University Press, 1985.

10/03/2003