In virtue of its very existence, it is impossible for any temporal event to issue from a complete determiner; for an eternal complete determiner would have its effect with it, co-eternal, whereas a temporal occurrence can never be eternal.
If it is said that one event follows another in succession from such a cause, then, in pre-eternity, it was not a complete determiner for anything at all; rather, it becomes a complete determiner for each event only at the very moment that event occurs. It therefore becomes evident that an eternal complete determiner produces neither a particular event nor the very class of events.
Should someone claim that it is a complete determiner for the class as such, we reply: that class exists only sequentially, so the determiner’s completeness would also have to be sequential, not eternal. Such sequential completeness can arise only if something comes to be within the cause, moment after moment. But for its completeness to reach its effect without any act arising in it is impossible; this would entail that the creature exerts an influence on the Creator without any act subsisting in the Creator by which He influences the creature.
Moreover, the emergence of temporal, variegated entities from a simple being in whom no act or attribute subsists is, to sound reason, impossible. Likewise, the strict concomitance of an effect with its agent is impossible: a temporal event is necessarily posterior, while the effect of a complete determiner can never be posterior to it.
Since the coming-to-be of the necessary events that are its prerequisite is impossible, and since what is necessitated cannot appear without its necessary concomitant, the appearance of the entire cosmos—both what is necessitated and its prerequisite—is impossible. This is precisely the point at issue.
The kernel of the proof is this: the pre-eternity of the world could be affirmed only if its Originator were an agent who necessitates by His very essence. Yet the rise of temporal events from such a self-necessitating agent is impossible. Therefore the world’s proceeding from a self-necessitating agent is impossible, and the world’s pre-eternity is impossible.