And this presents an even greater difficulty for them: that it should move through a motion imparted by something else.

If it is said, “We say of the perpetual action in the celestial sphere that proceeds from the Necessary Existent what would be said if that action subsisted in the Necessary Existent,” the reply is:

If the action subsists in that which has necessary existence in itself, then, on this view, nothing would prevent actions connected with its will and power from subsisting in it. Nor would it depend in any of this on any of its creatures. Rather, everything other than it depends upon it.

According to their position, however, no action can subsist in the First Principle, yet they say that the perpetual action subsisting in the celestial sphere proceeds from it successively.

They may therefore be told: If the celestial sphere has necessary existence in itself, then successive motions subsist in that which has necessary existence in itself. They cannot, therefore, maintain that actions cannot subsist in that which has necessary existence in itself.

If, on the other hand, the celestial sphere does not have necessary existence in itself, but is contingent in itself, then its essence, attributes, and actions all proceed from the First Principle.

If it is assumed to be eternal, its complete necessitating cause must likewise be eternal. The contingent celestial sphere is capable of successive motion, so it must depend upon a necessary being. Motion is contingent, not necessary in itself, and therefore requires an agent to bring it about successively. If the agent is assumed to be the celestial sphere, then its agent—the celestial sphere—is contingent. Thus, if these motions arise one after another, there can be no