The Six Books of Proclus on the Theology of Plato, Volume 2

For that each of things many will not be itself multitude alone, and again that each part of this will not be multitude alone is evident. But if it is not multitude alone, it is either united, or unities (εναδες). And if, indeed, it participates of the one it is united; but if it consists of things of which that which is primarily united consists, it will be unities. For if there is the one itself, there is also that which primarily participates of it, and which is primarily united. But this consists of unities. For if it consists of things united, again things united consist of certain things, and this will be the case to infinity. It is necessary, however, that what is primarily united should consist of unities. And thus we have discovered what we proposed at first, [viz. that every multitude consists either of things united, or of unities.]