and devised a doctrine combining the position of their predecessors—Aristotle and his followers—with that of the Muʿtazilī theologians and others like them. They divided existence into the necessary and the contingent, just as the theologians divided it into the eternal and the temporally originated.

This division was their own innovation; the earlier philosophers did not adopt it. Rather, their predecessors divided existence into substance and nine accidents, as is well known from the Categories, and placed the First Cause within the category of substance.

These later thinkers applied this division to the contingent, saying:

“Existence is either necessary or contingent, and the contingent must have a necessary existent. Thus, the existence of the necessary follows on either assumption.”

They imagined that this method they had devised for establishing the existence of the Lord of the worlds was a magnificent method, the highest attainment of rational minds. Yet it is among the most unsound methods and does not establish a Creator of the world at all. They must first show that these two categories exhaust all existence, and then demonstrate that the contingent, which they made the contrasting category to the necessary, entails the existence of the necessary existent they claim. This cannot be done on their approach.

For if they say:

“An existent either admits of nonexistence or does not. Whatever admits of nonexistence is contingent and must have a necessary existent,”

they may be told:

“If by that which admits of nonexistence you mean what is temporally originated, then the argument would establish a beginningless originator of temporally originated things. This is true. But according to you, what is beginningless may be necessary, or it may be