Trin. v. 10,Syn. 69, ‘God is One not in Person, but in nature,’ Trin. iv. 42, ‘Not by oneness of Person but by unity of substance;’ vi. 35, ‘the birth of a living Nature from a living Nature.’ Often enough the substance or nature of God or Christ is simply a periphrasis. The two natures in the Incarnate Christ are also mentioned, though, as we shall see, Hilary here also avoids a precise nomenclature.