They reply: “The agent must be existent when the act exists, and once the agent is absent the act cannot subsist.” Likewise, the cause must be present when the effect is present; the cause does not precede its effect. Even if one were to posit that every agent has a prior agent that produced it, this too would be impossible. Hence the impossibility remains, whether one says that the operative causes exist simultaneously or successively. Because the proof has shown that the cause must exist together with its effect and not before it, al-Rāzī stresses this consequence.

If you wish to see why the impossibility holds under both suppositions, consider this: it would require an endless series of originated causes and effects, and that is impossible whether imagined all at once or one after another. Each of them lacks existence in itself and, by its own nature, deserves only non-existence. Therefore, if they are all originated, produced, and fashioned, none of them could exist once the producing Maker is absent; they would resemble a succession of impossibilities and non-entities. Because this principle is well known, unanimously accepted, and treated at length elsewhere, we do not expand upon it here. Reason knows with certainty that occurrences cannot exist without an eternal First Producer.

The upshot is that al-Rāzī states: Everything that comes into being in the world cannot occur without a producer, and it is impossible that every produced thing should be produced by another produced thing. Consequently, the producer of every event must be an eternal agent. This directly contradicts their claim, for it stands as a brilliant proof that the originated entities