1. What are Kepler's two arguments that the sphere of fixed stars is not rotating?
2. What exactly is Kepler saying in the passage about cube roots and squares?
3. What is Ptolemy's defense of the elaborate model of spheres and eccentrics? AND: what is Kepler's response?
4. On the Aristotelian theory, how/ why do the fixed stars and planets move? AND: What is Kepler's response?
5. In what ways does Kepler's explanation of why the planets travel on ellipses instead of circles draw on ideas in Plato's Timaeus?
6. According to Kepler, could a planet (="celestial globe") move, if no outside forces acted upon it? Why?
7. According to Kepler, what moves the planets around in their orbits? How does he justify his view?
8. What does Kepler mean by his assertion that "a soul is present in the solar body"? What are his reasons for this claim?
9. How is the Sun like a magnet [="loadstone"], according to Kepler? (See also pp. 935-936; as well as 939)
10. Why, according to Kepler, do the planets take longer to complete their orbits than the Sun takes to spin once on its axis? (p.899)
11. Why, according to Kepler, do planets farther away from the sun move more slowly? (See also the lever analogy on pp. 933-934)
12. In what ways is the Sun's 'motive power' like light? How do we know that the motive power and light are not one and the same thing?
13. Does the Sun's 'motive power' count as an 'occult quality; of the sort Agrippa and the other magicians studied and hoped to understand?