efficient cause, and the impossibility (1) already mentioned follows. If, however, we make possibility the basis of dependence, it does not remain in the presence of the efficient cause as it did in its absence. For the essence, in the presence of the efficient cause, no longer remains possible at all. It is therefore known that origination cannot serve as the basis of dependence (2)).

It may be said in response:

This is of the same kind as the preceding argument, and it may be answered in several ways.

First, the fact that the essence [in the presence of the efficient cause] (3) no longer remains possible at all is a property that also holds when it is originated. Indeed, this is known only where there is origination, for the possible thing known to become necessary through an agent is an originated thing. As for what is eternal and beginningless, that is precisely the point in dispute.

The great majority of rational people say: We know by the self-evidence of reason that it can have no agent. Even supposing that the issue required inferential reasoning, the opponent has produced no proof whatsoever, since no evidence indicates (4) that anything in the world is beginningless. The utmost that sound proofs establish is the continuity of agency, and that is attained by originating one thing after another. In any event, there is no doubt that a possible, originated thing is necessary through its agent.

It may then be said:

If origination after nonexistence occurs through an agent, it entails the necessity of the originated thing; but if it does not (5) occur through an agent, origination is impossible. Thus, origination after nonexistence in the presence of the efficient cause is not the same as it is without the efficient cause: in the former case it is necessary, and in the latter it is impossible—just as a possible thing in the presence of the efficient cause is necessary, whereas without the efficient cause it is impossible,