gregory of nyssa - on 'not three gods'

"As we have to a certain extent shown by our statement that the word "Godhead" is not significant of nature but of operation, perhaps one might reasonably allege as a cause why, in the case of men, those who share with one another in the same pursuits are enumerated and spoken of in the plural, while on the other hand the Deity is spoken of in the singular as one God and one Godhead, even though the Three Persons are not separated from the significance expressed by the term "Godhead,"— one might allege, I say, the fact that men, even if several are engaged in the same form of action, work separately each by himself at the task he has undertaken, having no participation in his individual action with others who are engaged in the same occupation. For instance, supposing the case of several rhetoricians, their pursuit, being one, has the same name in the numerous cases: but each of those who follow it works by himself, this one pleading on his own account, and that on his own account. Thus, since among men the action of each in the same pursuits is discriminated, they are properly called many, since each of them is separated from the others within his ownenvironment, according to the special character of his operation. But in the case of the Divine nature we do not similarly learn that the Father does anything by Himself in which the Son does not work conjointly, or again that the Son has any special operation apart from the Holy Spirit; but every operation which extends from God to the Creation, and is named according to our variable conceptions of it, has its origin from the Father, and proceeds through the Son, and is perfected in the Holy Spirit. For this reason the name derived from the operation is not divided with regard to the number of those who fulfil it, because theaction of each concerning anything is not separate and peculiar, but whatever comes to pass, in reference either to the acts of His providence for us, or to the government and constitution of the universe, comes to pass by the action of the Three, yet what does come to pass is not three things."