“and the particular cognitions—namely, the practical intellect; and this applies not only to our volitional acts, but even to the volition by which the heavens themselves are set in motion.”

I said:
He has now made it clear that an unchanging cause does not entail anything changing, and that motion occurs only when particular conceptions and particular volitions come into being. Hence the question of how those very conceptions and volitions arise—the ones from which motion proceeds—is identical to the question of how motion itself arises. Yet, according to you, above them there exists only an unchanging reality that undergoes no origination, and an unchanging reality does not require that something changing issue from it. This would mean that contingent events either have no producer whatsoever, or that the complete cause of their origination is never in place. Instead, successive events of willing and conceiving would continually appear while nothing existed except an unchanging entity—and the unchanging cannot necessitate what is changing.

This alone demonstrates the invalidity of their position. From another angle: if a fixed cause cannot produce anything changing, then the Necessary Existent, in your doctrine, is a fixed cause; therefore, nothing changing can proceed from It—only what is fixed. If what proceeds from It is fixed, then what proceeds from that must likewise be fixed: the intelligible is fixed, and the soul, in itself, is fixed, so only something fixed can follow. Yet the successive conceptions and volitions, and the motion that issues from them, are changing states; and for them no cause remains—neither a fixed one nor a changing one.