The World, originally titled Le Monde and also called Treatise on the World, is a book by René Descartes (1596–1650). Written between 1629 and 1633, it contains a relatively complete version of his philosophy, from method, to metaphysics, to physics and biology.

Descartes was a follower of the mechanical philosophy, a form of natural philosophy popular in the 17th century. He thought everything physical in the universe to be made of tiny "corpuscles" of matter. Corpuscularianism is a viewpoint closely related to atomism. The main difference was that Descartes maintained that there could be no vacuum, and all matter was constantly swirling to prevent a void as corpuscles moved through other matter. The World presents a corpuscularian cosmology in which swirling vortices explain, among other phenomena, the creation of our solar system and the circular motion of planets around the Sun.

The work endorsed the Copernican view of the moving earth, so Descartes cautiously delayed its release when he heard of the condemnation of Galileo’s Copernicanism by the Catholic Church in Rome and the subsequent burning of the related works. Descartes discussed his work on the book, and his decision not to release it, in correspondence with another philosopher, Marin Mersenne. Some material from The World was revised for publication as Principia philosophiae or Principles of Philosophy (1644), a Latin textbook at first intended by Descartes to replace the Aristotelian textbooks then used in universities. In the Principles the Copernican tone was softened slightly with a relativist frame of reference. The last chapter of The World was published separately as De Homine (On Man) in 1662. The rest of The World was finally published in 1664, and the entire text in 1677.

Contents of The World

1. On the Difference Between our Sensations and the Things That Produce Them
2. In What the Heat and Light of Fire Consists
3. On Hardness and Liquidity
4. On the Void, and How it Happens that Our Senses Are Not Aware of Certain Bodies
5. On the Number of Elements and on Their Qualities
6. Description of a New World, and on the Qualities of the Matter of Which it is Composed
7. On the Laws of Nature of this New World
8. On the Formation of the Sun and the Stars of the New World
9. On the Origin and the Course of the Planets and Comets in General; and of Comets in Particular
10. On the Planets in General, and in Particular on the Earth and Moon
11. On Weight
12. On the Ebb and Flow of the Sea
13. On Light
14. On the Properties of Light
15. That the Face of the Heaven of That New World Must Appear to Its Inhabitants Completely like That of Our World

References

• Descartes, Rene. Le Monde, ou Traite de la lumiere. Translation and introduction by Michael Sean Mahoney. New York: Abaris Books, 1979. (French and English text on facing pages)

History of physics | Physics books