when the efficient cause is absent, nonexistent—indeed, necessarily nonexistent—and when it is present, existent—indeed, necessarily existent.

(* As for his statement: (“For origination is existence after nonexistence, whether that existence is through an agent or without an agent” *)

(1)

[this is an impossible supposition, for its existence without an agent is impossible. Thus, no origination after nonexistence can occur without an agent such that it could be treated alike in this state and when that state is absent.

Rather, this is like saying:

“The preponderance of its existence over its nonexistence is the same whether it is due to an agent or without an agent.”]

(2).

If, however, you mean by this that whatever serves as a cause, evidence, or condition in one of the two states cannot serve as such in the other, this is false. For if the cause (3) of the effect’s dependence upon the efficient cause is said to be possibility (4), origination, or both together, then it remains so without qualification. We know that what is originated can come into existence only through an agent, whether or not it has in fact come into existence, and that the existence of a possible thing cannot prevail except through something that tips the balance, whether or not it has in fact prevailed. Yet this dependence obtains only when it exists, for as long as (5) it remains nonexistent, it has no agent.

Your statement:

(“Otherwise, even in the presence of the efficient cause, there would remain a need for another efficient cause”)

establishes only the conceded meaning, not the disputed one. It establishes that its existence comes about through the efficient cause and that, in the presence of that cause, it needs nothing else; it does not establish that, in the presence of the efficient cause (6), there is no—