THEOREM 13.
That which first moves a circular motion is impartible, or without parts.
Demonstration.—For let A be that which moves the first motion: for it is necessary that there should be something of this kind, because everything which is moved is moved by something. But A, if it is that which first moves, will be immoveable: for that which is immoveable is the leader of all things which are moved. And, since it moves a perpetual motion, it will possess an infinite power of moving; for finite powers have also finite energies: for energy proceeds from power. So that if its energy is infinite, its power also will be infinite. Hence, that which first moves a circular motion, must necessarily either be body, or incorporeal. But if body, it is either finite or infinite. There is not however an infinite body. And if it is a finite body, it will not possess an infinite power. But the powers of things bounded according to magnitude are finite, as has been demonstrated. Hence, that which first moves a circular motion, is not a body. It is therefore incorporeal, and possesses infinite power.