 Informed by Dionysius notion of theophanic cosmic order, Eriugena is more comfortable with the complexities of Neoplatonic cosmology and with mediation (medietas) and less preoccupied with the issue of divine simplicity. Nevertheless, the Augustinian strain is not lost in Eriugena: both the human being and the creation have a Trinitarian structure. Along with Basil the Great, it is Augustine (through his great commentary on Genesis, De Genesi ad litteram) who teaches Eriugena to read and interpret the Hexaemeron (the creation account in Genesis 1) in a more literal and realistic manner and thus to counter-balance the more allegorical reading of Gregory of Nyssa;  Augustine constitutes both a foil and a catalyst for Eriugena’s thinking; his great challenge in the Periphyseon is trying to reconcile the Augustinian perspective with that of the Eastern thinkers.