When it was put to them:

“This follows only if their wills differ, whereas their wills may agree,”

they replied that, if the two ultimately agreed, the very thing done by one could not be the very effect produced by the other. For one’s independently performing an act and producing its effect precludes the other’s independently doing so. Rather, what one produces must be distinct from what the other produces.

This is the meaning of the Most High’s words:

“Then each god would have taken away what he had created” [al-Mu'minūn: 91].

But this is impossible, for the world is interconnected in such a way that the maker of one part cannot be independent of the maker of another, since some parts of the world depend on others.

Moreover, some of them would inevitably prevail over others. For the possibility we mentioned of their thwarting one another rests on the possibility that their wills might differ.

That possibility necessarily follows from each of them possessing power: if both possess power, their wills must be capable of differing.

If, however, it is supposed that their wills cannot differ but must agree, this would demonstrate even more decisively that neither possesses power. For if neither can will or do anything except what the other wills and does, it follows that neither possesses power unless the other makes him capable. It also follows that neither can possess power unless the other lacks it.