And since this is an inescapable consequence of their position, one of two things must follow: either their argument is invalid, or nothing comes into existence in the world. The second is disproved by observation; hence their argument must be invalid.
It is thus clear that they cannot escape the consequence that Abū ‘Abd Allāh al-Rāzī pressed upon them, and that al-Urmawī did not understand the actual force of this objection, so he countered it with something that does not undermine it.
The source of error and confusion here, however, is that when the term “infinite regress” does not refer to a regress in the act itself, it refers to a regress in effects—in the sense of something coming into existence—and also to a regress in what completes the agent’s being an agent.
For those who maintain that the complete cause and its effect coexist in time, as these proponents of an eternal world do, this requires whatever comes into existence to complete the cause to coexist with the effect rather than precede it. This demonstrates the invalidity of their argument.
As for someone who maintains that the effect comes into existence immediately after the cause becomes complete, he can adopt what al-Urmawī mentioned: that its being the cause of a particular effect is conditional upon something coming into existence, after which the effect follows, rather than coexisting with it.
But this invalidates their claim that anything in the world is eternal, and accords with the fundamental principle of the Sunnah and the scholars of hadith, who say:
“He has always spoken whenever He wills.”
For on their view, it may be said: His production of temporally originated things is conditional upon something coming into existence through which the cause’s causal efficacy becomes complete. Yet it is immediately after this completion comes into existence that the temporally originated thing comes into existence. On this basis, nothing in the world can be eternal, since something eternal can exist only together with its complete cause, whereas an effect’s coexisting with its cause in time is impossible.