The first ground:

It may be said: This is an objection to their statement: “The aggregate of contingent causes is contingent because it depends upon its contingent individual constituents. What brings the aggregate into existence cannot be one of those contingent causes, since it cannot be the cause of itself or of the causes preceding it. Thus, it cannot bring the aggregate into existence.”

The objector said:

“This would follow only if the cause of the aggregate were the cause of every one of its components. Why do you say that this is so?”

The first response to him is:

By the aggregate, we do not mean merely the collective arrangement; rather, we mean every individual constituent together with their collective arrangement. Accordingly, the cause of the aggregate is the cause of every one of its components. This is necessarily known: if a cause brings into existence the aggregate of individual constituents together with their collective arrangement, then it has brought every component into existence. For if it did not bring every component into existence, that component could be nonexistent. And if the aggregate were nonexistent—although the assumption is that the cause acts upon the aggregate so as to bring it into existence, and the aggregate consists of the individual constituents and their collective arrangement—then positing its nonexistence would entail combining two contradictories, which is impossible. This impossibility follows from supposing that the cause acts upon the aggregate so as to bring it into existence while also supposing that some of the aggregate’s components do not exist. It is therefore clear that its having brought the aggregate into existence entails the existence of