Cartesian Cosmology

The whole whole chain of truths which I discovered would have gotten me into trouble.

I have ever remained firm in my original resolution to suppose no other principle than that of which I have recently availed myself in demonstrating the existence of God and of the soul, and to accept as true nothing that did not appear to me more clear and certain than the demonstrations of the geometers had formerly appeared;

I have also observed certain laws established in nature by God in such a manner, and of which he has impressed on our minds such notions, that after we have reflected sufficiently upon these, we cannot doubt that they are accurately observed in all that exists or takes place in the world and farther, by considering the concatenation of these laws, it appears to me that I have discovered many truths more useful and more important than all I had before learned, or even had expected to learn.

But because I have essayed to expound the chief of these discoveries in a treatise which certain considerations prevent me from publishing, I cannot make the results known more conveniently than by here giving a summary of the contents of this treatise.

It was my design to comprise in it all that, before I set myself to write it, I thought I knew of the nature of material objects.

I am like a painter who is unable to paint all the parts of a body.

So I select the main part. I make the light fall only on that part, with the rest in the dark. I then let them appear only while I am looking at that main part.

A Light-first Science

This is why I focused on light. I then add something on:

• the sun and the stars, since light almost wholly proceeds from them
• the heavens since they transmit it
• the planets, comets, and earth, since they reflect it
• on all the bodies that are on earth, since they are either coloured, or transparent, or luminous
• on man, since he is the spectator of these objects.

I then make a new thought experiment on how our world was created by God from chaos.

The greatest part of the matter of this chaos must, in accordance with these laws, arrange itself to make the heavens, the earth, some planets, comets, sun and fixed stars.

I explained:

• the nature of light
• how in an instant of time light traverses the immense spaces of the heavens
• how from the planets and comets it is reflected towards the earth.

I respected the substance, the situation, the motions, and all the different qualities of these heavens and stars.

The Earth

I explained:

• why the Earth’s matter tended exactly to its centre even if God had given no weight to such matter.
• how with water and air on its surface, the disposition of the heavens and heavenly bodies, more especially of the moon, causes a flow and ebb as observed in our seas, as also a certain current both of water and air from east to west, such as is likewise observed between the tropics
• how the mountains, seas, fountains, and rivers might naturally be formed in it, and the metals produced in the mines, and the plants grow
• how all the mixed or composite bodies might be generated

and, among other things in the discoveries alluded to inasmuch as besides the stars,

Of the things that produce light, I only know fire. So I explained:

• its nature
• how it is produced and supported
• how heat is sometimes found without light, and light without heat
• how it can induce various colours and other diverse qualities on different bodies
• how it reduces some to a liquid state and hardens others
• how it can consume almost all bodies, or convert them into ashes and smoke
• how from these ashes, by the mere intensity of its action, it forms glass
  • This transmutation of ashes into glass was wonderful

God sustains the universe in the same way which he originally created it.

Although he had from the beginning given it chaos, he provided laws of nature to end up with the current universe.

In this way, things purely material might, in course of time, have become such as we observe them at present