Rising therefore to the One, we must add nothing to Him; we must rest in Him, and take care not to withdraw from Him, and fall into the manifold. Without this precaution there will be an occurrence of duality,[256] which cannot offer us unity, because duality is posterior to Unity. The One cannot be enumerated along with anything, not even with uniqueness (the monad), nor with anything else. He cannot be enumerated in any way; for He is measure, without Himself being measured; He is not in the same rank with other things, and cannot be added to other things (being incommensurable). Otherwise, He would have something in common with the beings along with which He would be enumerated; consequently, He would be inferior to this common element, while on the contrary He must have nothing above Him (if He is to be the one first Being). Neither essential (that is, intelligible) Number, nor the lower number which refers to quantity, can be predicated of the unique; I repeat, neither the essential intelligible Number, whose essence is identical with thought, nor the quantative number, which, because all number is quantity, constitutes quantity concurrently with, or independently of other genera.[257] Besides, quantative number, by imitating the former (essential intelligible) Numbers in their relation to the Unique, which is their principle, finds its existence in its relation to real Unity, which it neither shares nor divides. Even when the dyad (or "pair") is born, (it does not alter) the priority of the Monad (or Uniqueness). Nor is this Uniqueness either of the unities that constitute the pair, nor either of them alone; for why should it be one of them rather than the other? If then the Monad or Uniqueness be neither of the two unities which constitute the pair, it must be superior to them, and though abiding within itself, does not do so. In what then do these unities differ from the Uniqueness (or Monad)? What is the unity of the "pair"? Is the unity formed by the "pair" the same as that which is contained in each of the two unities constituting the "pair"? The unities (which constitute the "pair") participate in the primary Unity, but differ from it. So far as it is one, the "pair" also participates in unity, but in different ways; for there is no similarity between the unity of a house and the unity of an army. In its relation to continuity, therefore, the "pair" is not the same so far as it is one, and so far as it is a single quantity. Are the unities contained in a group of five in a relation to unity different from that of the unities contained in a group of ten? (To answer this we must distinguish two kinds of unity.) The unity which obtains between a small and a great ship, and between one town and another, and between one army and another, obtains also between these two groups of five and of ten. A unity which would be denied as between these various objects would also have to be denied as obtaining between these two groups.