Plotinos: Complete Works, v. 3 In Chronological Order,...

But when you say that the Man considered in himself is a number, as, for instance, a pair, because he is both animal and reasonable, we have here no more than a simple modality. For, while reasoning and enumerating we produce a quantity; but so far as there are here two things (animal and reasonable), and as each of them is one, as each completes the being of the man, and possesses unity; we are here using and proclaiming another kind of number, the essential Number. Here the pair is not posterior to things; it does not limit itself to expressing a quantity which is exterior to essence; it expresses what is in the very being of this essence, and contains its nature.