So the Father is God, the Son is God, and the Holy Ghost is God. And yet they are not three Gods, but one God.
And the question is whether this is coherent if "is God" is a predication rather than an identification. He says:
I can't see that it is coherent. If the first sentence expresses three predications (as opposed to three identity claims), then the divine nature must be thrice exemplified. If so, there are three Gods. Brandon may be conflating primary and secondary substance. God as primary substance is indivisible. But the divine nature, as something predicable, is a secondary substance and so must be be multiply exemplifiable.
The nature of apples admits of multiple exemplification (instantiation, realization). If you say that the divine nature does not admit of multiple exemplification, then how can three numerically distinct persons be divine, i.e., exemplify the divine nature?
I agree that the divine nature must be thrice exemplified, in the sense that there are three subjects that will have the nature; but I don't see that its being thrice exemplified implies that there are three Gods. Rather, there are three exemplifications of the nature; and whether or not this entails there are three Gods depends on how things with the divine nature are individuated. In other words, I see no reason to think exemplification and individuation are the same (I should have done more to make this clear originally). They are, of course, usually correlated in our experience. The nature of apples admits of multiple exemplification; but it also admits of multiple individuation. However, exemplification has to do with possession of form while individuation has to do with (for lack of a better term) division of that form into individuals separately possessing the form, and, as far as I can see, it is only if these two are equated that there would be any problem with the Quicunque Vult statement.
Vallicella goes on to say:
But if the divine nature is divided among subjects at all, then each of these subjects must be divine, which is to say that each must be a God.
If there are three distinct persons, and each is identical to God, then we have a contradiction. But if you say instead that each is divine (where the 'is' now expresses predication), then that amounts to saying that each is a God, which implies that there are three Gods.
But I don't see this. If the 'is' expresses predication, this does not amount to saying that each is a God but only that each is God. The issue, it seems to me, ends up depending again on what the divine nature allows in terms of individuation. And the divine nature can't be individuated like other things; there is no reason to think that multiple exemplification or realization of the divine nature implies individuation into separate Gods. (And if it did, it seems to me that this would be a fact about divine natures, not about multiple exemplification as such.)
I should be clear that I'm not claiming to be able to prove that the claim in the Athanasian Creed, taken as involving predication rather than identity, is consistent; but only that I don't see that there is any good reason to think it inconsistent (and thus presume it to be consistent until I'm convinced otherwise). That is, while I could just be confused, I don't see that there is any appearance of a contradiction; the apparent contradiction seems to derive not from the statement but from additional suppositions that I see no reason to think are universal or necessary (they must be both to generate the contradiction). My difficulty is that I cannot think of any possible non-question-begging arguments for the claim that, necessarily and universally, if a is P and b is P, and a is not b, there are two P's. It is usually the case; but this is just what happens to be implied by the nature of most P's we know, which tend to be corporeal and thus materially individuated; I see no reason to think it necessary and universal and thus applicable to God.
