The thinker whom they strive to imitate—Aristotle—never addressed questions of existence, necessity, contingency, and the matters that follow from them. It was Ibn Sīnā who took up that terminology, borrowing it from the Muslim mutakallimūn.

We therefore say to these people: This celestial sphere, which moves with what you call a “yearning motion,” is either contingent in itself—dependent upon a Maker who brings it into being—or necessary in itself. If it is contingent, its Maker must also be the One who sets it in motion, for He who originated its very essence is all the more able to originate its motions. In that case, you need not strain to devise some separate theory for the origin of those motions.

Should the sphere’s motions be volitional, it is perfectly plausible that the movers are angels who set it in motion by the volitions within them, and that those very volitions are acts of worship directed to God—neither an attempt to imitate Him nor a quest for something unattainable.

Indeed, their discourse about the sphere’s goal in its motion is like the talk of children. They claim that the sphere’s sole aim is to move perpetually, producing “forms and configurations” which it knows full well it cannot truly generate—rather like someone who spends his whole life circling the same spot because perfect motion would be to move from eternity past to eternity future, and, being unable to do so, he spins round the little space he can. Such behavior is closer to the antics of madmen than to the deeds of rational people.