Circularity (dawr) is of two kinds. The first is antecedent—or sequential—circularity. This is impossible by the unanimous judgment of rational people. An example is to say, “This can occur only after that, and that can occur only after this.” Such a claim is self-evidently impossible, for a thing cannot be before it exists, nor can its existence be delayed after it exists. If one were to maintain that a thing comes into existence only after it has already come into existence, the impossibility would be obvious. How much more absurd, then, to assert that this depends on that while that in turn depends on this. One is thereby forced to concede that each thing is both before itself and after itself. The vicious circle would surface four times over: for when it is said, “This occurs only after that,” “that” is made prior to “this”; and when it is said, “That occurs only after this,” “this” is made posterior to “that.” Accordingly, “this” would have to exist only before “that,” which is before “this,” and “that” would have to exist only before “this,” which is before “that.” Thus “that” precedes itself by two steps, and “this” precedes itself by two steps. Hence all rational minds agree that such a notion is impossible.

The second kind is concomitant—or simultaneous—circularity, as when one says, “This exists only together with that, neither before it nor after it.” This is permissible, just as one says, “Fatherhood exists only together with sonship,” or as theologians state that the Lord’s essential attributes exist only together with His Essence—His knowledge alongside His life, His power alongside His knowledge, and so forth.