Richard of St. Victor continues along the same lines concerning the unity of the divine being in Chapter Two, grouping divine attributes into little trinities again. But here he begins to make a bit of a shift in that the predicates of God which he considers strike more at the heart of whether the divine being can be given to another, and if so how it could be possessed. For if the divine substance is one, it can not be possessed by another in a way that would set that substance over against itself.
As we contemplate created being, Richard takes pains to demonstrate that the multiplicity of being in the created order is not the result of each existing thing possessing being out of itself, but rather by a participation in the being of God. He states it as God being generous to some in regards to certain attributes, while ‘tight-fisted’ in regards to others. Thus, one being may participate to a greater extent in God’s power, while another may have more of a share in God’s wisdom, etc. This differentiation in participation marks off each being as its own kind of thing, thus giving rise to the multiplicity of being that is immediately evident to the reason and experience. And as God is the only one who possesses the fullness of being per se, all other being only participates in his being, thus clearly distinguishing between Creator and created.
Given this approach to the fullness of being as possessed by God, there can only be one fullness of being, or else another supposed divine being would be simultaneously greater and less than itself, since it would be greater in power but lesser in wisdom, etc. As such, the divine substance- what it is to be God- can only be one, and this absolute unity must obtain for whatever one might predicate of God. The implication of this indivisibility of the divine substance is that whatever we might say about the divine persons (i.e., the Trinity), the distinctions between persons cannot be found on the level of substance nor explained by means of attributes. The Father cannot be identified absolutely with power, nor the Son with wisdom, nor the Holy Spirit with holiness, for in doing so one would necessarily state that the divine being can be differentiated in regards to substance, which would mean that in some respect another substance could be greater, thus destroying the absolute co-incidence of the divine attributes in God.
As Chapter Two closes, we come face to face with the absolute oneness of the divine being. While this might seem to make any speculation about the Trinity impossible, Richard is up to something, for it is out of the absolute coinciding of perfections in the divine substance that the necessity of three divine persons arises.