spheres, such as the epicycle and others.

As for anything existing beyond these for which they have no evidence, their method provides them with no knowledge either to deny or to affirm its existence.

Likewise, the claim that the motion of the ninth sphere is the origin of all events is erroneous and misguided even according to their own principles. For they say that the eighth sphere, with the fixed stars it contains, has a motion peculiar to it, and that this motion has two poles distinct from those of the ninth sphere. The same applies to the seventh and sixth spheres.

If each sphere has a motion peculiar to it, and the differing motions cause the various celestial configurations that arise, while those configurations cause events in the lower world, then the motion of the ninth sphere is only part of the cause, like the motion of any other sphere. The configurations that arise in the heavens include the conjunction of one celestial body with another at the same degree; its opposition to another when half the celestial circle, or one hundred and eighty degrees, separates them; its trine with another when a third of the circle, or one hundred and twenty degrees, separates them; its square with another when a quarter of the circle, or ninety degrees, separates them; and its sextile with another when a sixth of the circle, or sixty degrees, separates them. These and similar configurations arise only through differing motions, each distinct from the others. The motion peculiar to the eighth sphere is not identical to that of the ninth, even though it follows the ninth in the overall motion—like a person moving aboard a ship in the opposite direction to its motion.

Likewise, the motion peculiar to the seventh sphere does not derive from either the ninth or the eighth. The same applies to all the other spheres: the motion peculiar to each does not derive from the spheres above it. How, then, can the motion of the ninth sphere alone be made the origin of all events, as claimed by someone who supposed the Throne to be dense?! Moreover, according to them, the ninth sphere is simple, its parts are homogeneous, and there is no variation within it whatsoever. How, then, could it cause differing effects independently of the things receiving those effects and of other causes? Yet