—the one who is capable will inevitably subdue the other and rise above him, just as the Almighty says,

“and some of them would surely have gained ascendancy over others”
(Qur’an 23:91).

These points are dealt with at length elsewhere, when we discussed the various ways people seek to establish the oneness of God and what that doctrine entails.

What concerns us here is that it is impossible for there to be two necessary beings whose power is conditional upon one another’s power. The Lord must be powerful in and of Himself; His power is an essential attribute of His very being, and what is essential can never be separated from that to which it is essential. If He has always been powerful, then He has always been able to act upon what lies within the reach of His power. Were the performance of an act not eternally possible, He would not have been powerful from all eternity; rather, He would have become powerful after previously not being so.

This is not a case of the permissible simultaneous circularity sometimes cited, such as when one says, “This cannot be capable unless that is capable.” Such mutual dependence can occur among created things that are both effects of one and the same cause, for they come into being through a single agency. In that situation, if two agents are empowered by a third, the power of each may be conditioned on the power of the other, like two interdependent phenomena, neither of which—together with its effectiveness—exists without the other and its effectiveness.

By contrast, consider two eternal, necessarily existent creators who do not derive their power from a third. To claim that the power of either is contingent on the power of the other would amount to antecedent circularity: if one possesses no power from himself and none from a third, it must come from the other—an obvious logical circle. And if someone were to say that his power comes jointly from himself and from the other, we would reply that what is found in him would still be contingent on his own power; hence he must possess a power that is entirely independent, in no need of anyone else, and for which no other can be a pre-condition. That power must therefore be intrinsic to his essence—which is precisely what we set out to demonstrate. If power is indeed intrinsic, it is impossible for either of them to become powerful after having been powerless, and equally impossible for the act to become possible after previously having been impossible.