Gregory Of Nazianzus’ Trinitarian Argument in Oration 23

In his Third Oration on Peace Gregory of Nazianzus seeks to refute Eunomian claims that the Son and Spirit do not proceed from God’s essence and, therefore, are not fully divine. To do so, Gregory modifies a piece of triadic speculation – used by Origen and others – to fit his particular polemical and doctrinal needs. My aim in this study is to give an exposition of Gregory’s argument. After outlining the main points of Eunomius’ view of the Son’s deity, I investigate the four dilemmas that compose Gregory’s anti-Eunomian argument. The argument is negative insofar as it attacks Eunomius’ brand of trinitarianism directly. Even so, in the wider rhetorical context of Oration 23 this argument leads naturally into a positive account of the Father’s essential production of the Son and Holy Spirit. I conclude by detailing some of the main moves of this positive trinitarian theology.