of the two constituents is distinct from the composite whole formed from them. Thus, each constituent can be conceived without knowledge of the composite formed from them, and what is known is distinct from what is unknown. Whatever depends on something else for its existence is contingent, not necessarily existent in itself, since being necessarily existent in itself means nothing other than not depending on anything else for one’s existence. These impossibilities arise only from positing a plurality of beings necessarily existent in themselves; such a plurality is therefore impossible.

He said:

“Some of our associates have also turned to this line of argument to establish divine oneness. Yet it is weak, for an objector could say: Even if we concede that the two agree in one respect and differ in another, and that what they share is necessity of existence, why do you maintain that this is impossible? What you mentioned in the first argument would follow only if what is designated as necessity of existence were a positive reality. But if it were a negative notion expressing an absence—namely, the absence of any dependence of existence on an external cause—those consequences would not follow. Why, then, do you maintain that it is a positive reality?”

He then elaborated on its being a notion expressing an absence, in a discussion that does not belong here.