Enneads VI.6: Of Numbers
Unity and Number Precede the One and the Many Beings
In general, everything which is predicated of an object either comes to it from without, or is its actualization. Unless by nature it be inconstant, being present now, and absent then, if it be always present, it is a being when the object is a being. If it be denied that its nature were that of a being, it will surely be granted that it is a part of the essences, and that it is an essence. Now, if the object can be conceived without the thing which is its actualization, this thing nevertheless exists contemporaneously with it, even though in thought it be conceived posteriorily. If the object cannot be conceived without this thing, as man cannot be conceived of without one, in this case one is not posterior to man, but is simultaneous, or even anterior, since the man’s subsistence is entirely dependent thereon. As to us, we recognize that Unity and Number precede (Essence and the essences).
UNITY MUST EXIST IN THE INTELLIGIBLE BEFORE BEING APPLIED TO MULTIPLE BEINGS.
11. It may be objected that the decad is nothing else than ten unities. If the existence of the One be granted, why should we not also grant the existence of ten unities? Since the supreme Unity (the unity of the first Essence), possesses hypostatic existence, why should the case not be the same with the other unities (the complex unities contained within each of the essences)? It must not be supposed that the supreme Unity is bound up with a single essence; for in this case each of the other (beings) would no longer be one. If each of the other (beings) must be one, then unity is common to all the (beings); that is that single nature which may be predicated of the multiple (beings), and which must, as we have explained it, subsist in itself (in the primary essence) before the unity which resides in the multiple (beings).