This chapter sets out Maimonides’ cosmology. This is a heavily Aristotelean system, and sounds jarring to the modern ear. This chapter summary is incomplete…

this Universe, in its entirety, is nothing else but one individual being: that is to say, the outermost heavenly sphere, together with all included therein, is as regards individuality beyond all question a single being like Said and Omar

The structure of the Universe is as follows:

  • there is an outermost heavenly sphere, which forms the outer limit of the Universe and which contains everything that is not God
  • there are spheres “enclosed within another so that no intermediate empty space, no vacuum, is left”
  • each sphere rotates at a constant speed, but the various spheres have different speeds; the “outermost, all-encompassing sphere, revolves with the greatest speed; it completes its revolution in one day, and causes everything to participate in its motion”
  • the spheres are not concentric; some of them share a center with the center of the universe, while others do not.
  • stars and other heavenly bodies are ‘embedded’ into the spheres.
  • there are at least 18 spheres, and possibly more; “this is a matter for further investigation”
  • some things about the four elements and their natures.

This cosmology works together in harmony through a special force:

There also exists in the Universe a certain force which controls the whole, which sets in motion the chief and principal parts, and gives them the motive power for governing the rest. Without that force, the existence of this sphere, with its principal and secondary parts, would be impossible. It is the source of the existence of the Universe in all its parts. That force is God: blessed be His name!