 Main themes of the treatise include distinguishing a whole family of senses of “one” (in a few cases Fârâbî also gives the corresponding senses of the abstract “unity”), but also and especially distinguishing different ways that senses of “one” are related to senses of “many”. The treatise can read like a dry catalogue, and Fârâbî rarely gives arguments or admits that his claims might be controversial, but it is often clear that he has an opponent in mind. That opponent might be a type rather than a particular earlier philosopher, but it seems likely that it is specifically al-Kindî. Kindî had argued in On First Philosophy that any thing other than God that is called “one” is many as well as one, and therefore that it is one not essentially but only accidentally, indeed that it is one only improperly or “metaphorically”; and he argues that such a thing can be one only through participation in some unity extrinsic to it, which (to avoid infinite regress) must be purely one and not also many. Kindî also argues that any many is a collection of ones: and since everything is either one or many, and any many depends on ones, and any one depends on a pure one, and God is the only pure one, everything owes its existence directly or indirectly to God. While Kindî, like Fârâbî, gives a long list of different kinds of things that can be said to be one, and while he has different reasons for disqualifying each of them from being a pure one, i.e., a one that is not also many, typically he seems to think that each of these senses of “one” is predicated of some subject which is many, so that if the unity were removed, that underlying multiplicity would remain. Kindî infers that each of these ones is a many-that-is-one, and therefore that it has contrary attributes, and therefore that it is not essentially one, and even that it is only metaphorically one, since (as he argues in a tradition going back to Zeno of Elea and to the first Hypothesis of Plato’s Parmenides) for something to be truly one is for it not to be many in any way, e.g., by having many  constituents.[34]