—thus neither would bring any part of the world into existence, which would amount to joining two mutually exclusive states. If, however, one of them could act only when the other refrained, his power would be contingent upon the other granting him leave. Likewise, if neither could act except with the help of the other, it would follow that neither possessed any power unless the other first made him able. In that case, taken separately, neither would have power over anything at all; and if each lacks power in isolation, their having power together is likewise impossible, for there is nothing outside the two to endow them with power, and neither possesses an intrinsic ability by which he could assist the other. Were each to become capable only through the other’s making him so, the result would be a vicious causal circle—an antecedent circularity that all rational minds agree is impossible, its absurdity being self-evident once conceived.

This differs from a situation in which a third agent endows them with power when they are together; such a case involves concurrent circularity, which is admissible. For this reason you will never find two existing things that acquire power merely by being together unless a third brings that about for them, or unless the strength of one augments the strength of the other. Among human partners, for example, at least one of them must possess some power on his own, or their combined power is but a reinforcement of what already exists.

In our hypothetical, however, no power at all is affirmed for either of them when taken alone. Now, to posit an equal to the Lord would require that this equal possess power identical to His, yet the notion of two all-powerful deities is impossible, which proves that no equal exists. And since imagining them both powerless is equally impossible, it is evident that in every respect no partner exists for Him. Whether one supposes an equal or a co-sharer, the very supposition is intrinsically absurd.