On the Heavens
Four books present a finite, ordered and eternal universe, then examine celestial motions and the elements. Earth occupies the center while celestial bodies follow supposedly natural circular motion.
Understanding the text
The work shaped cosmological history; its physical claims remain historically important but are largely superseded.
Key points
- 01
Aether
A simple body distinct from the four terrestrial elements explains the supposed incorruptibility of the heavens within this system.
- 02
Natural places
Heavy and light are defined through movement toward particular cosmic regions rather than through universal gravitation.
- 03
One world
The argument against multiple worlds depends on the theory of elements and their natural destinations.
How to read it
Draw the model and distinguish astronomical observations from physical assumptions and metaphysical arguments.
Editions & sources
- Consult the reference 1classics.mit.edunew tab
- Consult the reference 2plato.stanford.edunew tab
- Consult the reference 3classics.mit.edunew tab
Summaries and key points are original editorial interpretations. They accompany reading the work and do not replace an edition of the text. Editorial method ↗