cannot be its own Lord, nor does the Lord Himself need it in any respect in order to create it (1); for if He needed it in order to create it, He could not create it until it existed, while it could not exist until He created it. That would entail circularity in prior dependence, not simultaneity (2).

Since it cannot exercise causal influence upon itself, then, all the more so, it cannot exercise causal influence upon that which exercises causal influence upon it (* If two necessary beings were posited, each having some causal influence upon the other, each would necessarily exercise causal influence upon that which exercises causal influence upon it *) (3). This is impossible [as has been shown] (4). It is therefore impossible to posit two necessary beings, each of which exercises causal influence upon the other in any respect. Consequently, that which is necessary in itself cannot depend upon another for any of its necessary concomitants, whether that other is posited as necessary or contingent.

This also establishes the impossibility of the universe having two makers. For if the two makers were independent, each having made everything, this would be intrinsically contradictory [impossible] (5). If one of them made even part of it, that would preclude the other from independently making that same part—so how could each have independently made all of it?!

For this reason, rational people (6) agree that two complete causal agents cannot concur in producing a single effect, for that would combine two contradictories: its having come into existence through this one alone (7) contradicts its having been