dependent on it in any respect; for whenever one is dependent on something in any respect, it can exist only through that thing.
Indeed, whatever exists does so only together with the existence of its necessary concomitants, and its existence is not complete without them; therefore anything that is assumed to need something else cannot exist except by means of that other.
Accordingly, if each of the two alleged eternals were in need of the other, it would follow that the first could not exist unless the second created whatever satisfies the first’s need, and the second could not exist unless the first created whatever satisfies the second’s need.
Yet a creator is not a creator until he first exists, and he does not exist except together with the requisites of his existence. Hence this one would not exist until the other made him exist, and that one would not exist until this one made him exist; for inasmuch as his bringing into being that through which his own existence is completed depends on the other, his existence hinges upon that other and he cannot exist without it. There is therefore no difference between one of them needing the other for his very existence and his needing him for something without which that existence is incomplete. This is the “prior circularity,” whose impossibility is agreed upon by all rational people.
As for “simultaneous circularity,” which is the case where this does not exist except together with that and that does not exist except together with this—like fatherhood with sonship, or the various attributes of the Lord in relation to one another and to His essence—He is not Knowing unless He is also Powerful, nor is He Knowing and Powerful unless He is Living, and He is not Living unless He is Knowing and Powerful. His attributes do not exist apart from His essence, and His essence is not realized apart from His attributes. Such mutual concomitance is admissible between two created things that both depend on the Creator who brings them into being, like fatherhood and sonship, and it is likewise admissible with respect to the Lord, exalted is He, who is inseparable from His attributes.
But if two eternal, unoriginated deities, both acting, were posited, it would be impossible for either of them to be in need of the other, since his existence would not be complete except through that upon which its completion depends, and he could not act upon anything until his own existence were complete; consequently it is impossible once each of them is deficient in