and He—glorified be He—is the originator of all changing effects and of their changes. It is therefore impossible for those effects to bring about a change in His act, which subsists in Him; for this would mean that the effect—the created and fashioned thing—affects the Creator and Maker, whom they call a [complete] cause (1). This would entail an impossible causal circle. Indeed, for each of two things to affect the other, without there being a third thing distinct from both that affects (2) them, is an impossible circle of causal priority. Neither of the two agents can act upon the other until the other acts upon it, as in the case at hand. The temporal change cannot occur until He causes it to occur by means of the act subsisting in Him. But if that act could not subsist (3) until that change brought it about, it would follow that the act could not exist until the change existed, while the change could not exist until the act existed. Consequently, neither of them could exist until it had itself existed two stages before its own existence, which would entail the conjunction of contradictories twice over.

If it is said:

“The first changing effect brought about a change in the agent, and that change necessitated a second change.”

The reply is:

“That first effect arose solely from an act subsisting (4) in the agent. Thus it is the agent, by means of the act subsisting in Him, who brings about every temporal, changing thing other than Himself, from first to last; nothing else whatsoever affects Him.”

If it is said that the existence of His second effect is conditional upon His first effect, He is nonetheless the agent of both the first and the second. He therefore needs nothing other than Himself in any part of His act, nor is He affected by