The concern here is religion, with these proofs of the dependence of contingent beings on a necessary being external to them.

By their expression, “the totality of what the aggregate of contingent beings depends upon,” they mean the fully sufficient cause: the fully sufficient determining factor whose existence, through its complete causal action, necessarily entails their existence. As we have explained, when an agent acting by choice has complete power and complete will, the object of that power must exist—namely, the contingent beings.

As for his question, “Why do you say that this necessarily entails that some part of the aggregate suffices for the whole?” the answer follows from what we have explained: a fully sufficient cause necessarily entails the existence of its effect. If the fully sufficient cause of the aggregate is assumed to be part of that aggregate, it follows that some part of the aggregate causes the whole, and thus causes both itself and other things.

This is evident. If we posit the aggregate of contingent beings and suppose that one of them causes both itself and the others, then some part of the aggregate would necessarily bring about the existence of the aforementioned whole while itself belonging to that whole. This is impossible. In an aggregate composed of a necessary being and contingent beings, however, no part causes every individual member and their collective configuration 0. For that aggregate includes the being that exists necessarily through itself, which nothing has caused. The distinction is therefore clear.

Moreover, the necessary being causes the contingent beings and their collective configuration, but does not cause itself. This differs from the aggregate of contingent beings: each of them must have a cause, and their combination must also have a cause. Thus, the aggregate depends upon a cause under any interpretation