Consider it also in this way. If the world, you said, was made later, while He existed before, the impassible and unchangeable God must change; for the one who first makes nothing, and afterward makes, must of necessity change and be altered, from not making to making. — Yes, I said. — But has God at some time ceased from making the world, or not? — He has ceased. — For otherwise it would not yet be completed. — True.
— If, then, making, as opposed to not making, condemns God of alteration, does not also not making, as opposed to making? — Necessarily. — But would you say that He has been altered today by not making, in comparison with when He was making? — By no means. — Then neither, when He was making the world, is it necessary that He was altered in comparison with what He was when He was not making; and so neither is it necessary to say that the universe must coexist with Him—on the ground of not being compelled to say He was altered—nor that it is coeternal for this very reason.