and when it is necessary in the presence of the efficient cause despite being originated, it does not thereby require another efficient cause.

The second response is to say:

Regarding his statement:

“The essence, in the presence of the efficient cause, no longer remains possible at all,”

if he means that it no longer remains dependent upon the efficient cause, or that the ground (1) of its dependence is no longer possibility, this is false and (2) contrary to what they consistently maintain. If, however, he means that its nonexistence is no longer possible because it is necessary through another, this contradicts their assertion that, considered in itself, both its existence and its nonexistence are possible even though it is necessary through another. Accordingly, their claim is invalidated (3)—namely, that something eternal and beginningless can be possible. Thus, nothing eternal and beginningless is possible (4). By contraposition, no possible thing can be eternal and beginningless. It is therefore established that every possible thing exists only after having been nonexistent, which is precisely what was to be proved.

Once the doctrine is invalidated, all its proofs are likewise invalidated, since the claim follows necessarily from those proofs; when the consequent is negated, all the antecedents are negated as well.

The third response concerns his statement:

“The basis of dependence cannot remain in the presence of the efficient cause as it did in its absence.”

Do you mean that what depends upon the efficient cause does not exist when the efficient cause is absent [as it does when the efficient cause is present] (5)? Or do you mean that the cause of its dependence, the condition of its dependence, or the evidence of its dependence differs between the two states? If you mean the former, that is correct. For what is originated after nonexistence is not the same in the presence of the efficient cause as it was in its absence, for it is—