He said:

“This entails the existence of a necessary being, and this is self-evident. But it does not entail that this being has no cause; that requires a separate proof.”

This statement of Ibn Rushd rests on the self-evident dependence of what is temporally originated upon an originator, as the majority maintain.

If what is meant by the genuinely possible is what is temporally originated, then it must have an agent that is not temporally originated. This is what rational people generally call necessary: everything beginninglessly eternal is necessary according to them, and everything possible in the specific sense is temporally originated. Beyond this lies the question of its having no cause.

It is known that an infinite regress of this kind—where each temporally originated thing has an originator, and so on without end—is impossible according to all rational people. This has been explained in its proper place.

As for the claim that the possible, which is beginninglessly eternal and necessary in existence, is caused by another, this likewise does not establish the impossibility of an infinite regress on that supposition, as explained above. On this supposition, al-Ghazālī’s contention that their argument against an infinite regress is invalid on their own principles can be substantiated. For if every possible being is assumed to be caused, despite being necessary and beginninglessly eternal, the same argument applies to its cause as to the being itself. Thus, if an endless series of causes and effects is posited, each necessary and beginninglessly eternal, the impossibility of this is not apparent on that supposition. Nor is it apparent that their totality requires a necessary being outside itself, since each member is necessary and has a cause.

If it is said, “The totality has no cause,” the impossibility of this is not apparent, as it is in the case of temporally originated things. But whether it has