not one of them exists through itself; rather, each depends upon that which originates it and brings it into being.

The second shares this characteristic with the first in every respect. Neither any individual member nor the aggregate has existence from itself; hence nothing would exist at all.

Indeed, when someone says, “This exists through another, and so on without end,” or, “This was originated by another, and that other was made manifest by yet another, continuing to an endpoint,” what his statement really amounts to is postulating infinitely many nonexistent things.

For a postulated agent, if it does not exist through itself, has nothing of itself but nonexistence; its own agent, too, has been postulated as having nothing of itself but nonexistence.

None of the members of this successive series has anything of itself but nonexistence, nor does the aggregate have anything of itself but nonexistence. There is nothing here beyond the individual members and the aggregate, and nothing but nonexistence proceeds from either. Thus, what has been postulated is an aggregate from which nothing but nonexistence proceeds. Such a thing cannot give rise to existence, for existence cannot proceed from something that yields only nonexistence, whether as an aggregate or through its individual members.

Thus, if a successive series of contingent beings is postulated, each of which has no existence from itself, there would be nothing but nonexistence. Yet existence is a perceptible reality. It is therefore known that among existing things there is that which exists through itself, whose existence is not derived from another. This is what was to be established.