Dunamis and Christian Trinity in the fourth century

The teaching of Gregory of Nyssa on the Trinity has been explored in the light of late antique logic by a number of recent authors, notably Johannes Zachhuber in Human Nature in Gregory of Nyssa (Berlin, 2000) and in his subsequent exchange of articles with Richard Cross. The evolution of Aristotelian logic in late antiquity has also been the subject of perceptive and innovative works by scholars such as Ricardo Chiaradonna, Sten Ebbesen and Steven Strange. Most of these studies have been undertaken without reference to theology; the present article will consider whether the difficulties of Gregory’s argument could be tempered, not so much by the direct application of ancient logical theories, as by reflection on what the theorists have to say about the nature and purpose of Aristotelian logic. A secondary goal of the article will be to reconcile the simile of the rainbow in [Basil], Letter 38 with the meteorological phenomena, making use of other ancient writings on the same topic and of modern work on ancient perceptions of colour