One critical fault: The translator opts for “But monotheism we hold in honor” when all other renditions have “But Monarchy is what we hold in honor.” As Gregory is contrasting Christianity with Judaism, a simple monotheism doesn’t make sense.
The Claims of Knowledge
St Gregory’s opponents, the Eunomians, reduced God to a set of deductive proofs. Unlike the earlier Gnostics and Arians, their problem was not that God was unknowable, but that he can easily be reduced to what the mind can affirm or negate.
On the Son
Gregory defines monotheism as “single rule produced by equality of nature, harmony of will, identity of action, and the convergence towards their source of what springs from unity—none of which is possible in the case of created nature” (29:2). This allows “numerical distinction without division in substance. In this way a One eternally changes to a Two and stops at a Three.”
St Gregory makes an important point in saying that the Son and Holy Spirit are from God but not after him. They have a cause, and thus are not unoriginate, but it is not a temporal cause. He is very quick to affirm the co-eternality of the Son and Holy Spirit with the Father.
Like St Athanasius, St Gregory operates around a series of terms, which determine the debate. They are “Ingenerate, The Begotten, and ‘what proceeds from the Father’” (28:2). Gregory is careful to affirm that Ingeneracy is not God’s substance (29:12). This is a necessary point because the Son is not ingenerate (since he is begotten), but the Son is of the same substance as the Father.
The term “Father” designates neither the activity nor the substance, but the relationship which holds good between the Father and the Son (29:16). This rebuts the dilemma posed: if we say that Father designates the “substance,” then we admit the Son is of a different substance than the Father. If we say “activity,” then we admit the Son is a creation of the Father. If we say “relationship,” however, we can affirm Trinitarianism.
Gregory concludes by saying that “each member of the Trinity is in entire unity as much with himself as with the entire partnership, by identity with being and power (31:16).