say that a fully effective agent must coexist with its effect, or that its effect cannot lag behind it. For nothing among created things is, by itself, a fully effective agent at all. This is observable through the senses in all agents, whether they act through will and choice, as animals do, or by nature, as inanimate bodies do. None of them acts independently. Fire and similar things, for example, burn only in conjunction with another cause: a subject capable of being burned. Likewise, a human being acts through his will and power only with the aid of causes beyond his power.

Furthermore, whatever else is subsumed under the universal proposition must either be living and possess a will, or be nonliving and possess only a natural disposition. On either supposition, these things produce acts after previously not producing them, as is observable in all agents. Yet the disputant says that they do not produce an act until they undergo change, and that change is impossible for the Lord.

He may be told: This objection would be valid only if someone other than you were arguing by analogy with these things, and you then drew a distinction. The point here is that you yourself cannot formulate a universal proposition encompassing two or more things to establish the impossibility of an act proceeding from an essence after