[Circularity Is of Two Kinds]

it is permitted in both, as held by most hadith scholars and philosophers. This is discussed fully elsewhere.

Circularity, likewise, is of two kinds:

The first is prior circularity: one cannot exist until after the other, while the other cannot exist until after the first. This is impossible by universal agreement among rational people. As for simultaneous, correlative circularity, it is exemplified by two inseparable correlates that exist at the same time, such as fatherhood and sonship; one thing’s being above another together with the other’s being below it; and this thing’s being to the right of that one together with the other’s being to its left (1). The same applies to other inseparable relations that exist only together. This kind of circularity is possible. If neither is the agent of the other nor a constituent necessary to complete the agent (2), but their agent is something other than either of them, then this is possible.

If, however, one is the agent of the other (3), or is part of what makes the agent an agent, it becomes a form of impossible circularity.

[The Impossibility of Two Gods Existing]

For this reason, there cannot be two Lords who act either independently or cooperatively. As for two independent Lords, if one of them were solely responsible for the world (4), this would require that (5) the other have no share in it. If the other were likewise solely responsible for it, each of them would necessarily have brought it about, while each of them would also necessarily not have brought it about. This combines two contradictories.

As for two cooperating Lords, if it were said that each could act independently while the other was independently acting upon it (6), this would entail the power to bring two contradictories together, which is impossible,