Considered in itself, the thing is contingent in existence. The truth, however, is that its very essence is contingent in and of itself, while—on the condition of its non-existence—it is impossible for it to exist, and—on the condition of its existence—it is necessary that it exist. One must distinguish between saying, “The existence of Zayd, who presently exists, is necessary,” and saying, “The existence of Zayd, so long as he exists, is necessary.” In the same way, there is a difference between the statement, “The persistence of an originated entity is necessary by its essence,” and the statement, “Its persistence is necessary on condition—namely, so long as it exists.” The first assertion is false; the second is true. Thus, if we omit mention of that condition, the persistence of its existence is not necessary.

Understand also that whatever renders a thing’s existence necessary simultaneously renders its non-existence impossible. It is inconceivable that in the state of non-existence the thing should be merely possible, only to become necessary in the state of existence. The entity in itself is contingent: it can fail to exist, and it can exist. Whichever of the two states you make the condition for its continuance, once you link its continuance to that state it becomes, under that condition, necessarily judged rather than merely possible—and no contradiction arises. Contingency pertains to the thing considered in itself, whereas necessity and impossibility attach to a subsequent condition imposed upon it.

If matters stand thus, then what is contingent in itself never possesses necessary existence without qualification. As long as its very essence remains what it is, it is not necessary of itself but through another and by virtue of a condition; its existence therefore remains dependent upon something outside itself, and whatever is in need