In this chapter Tolan reflects on the way in which the doctrine of Divine Ideas, causa exemplaris, has been used as a way to reconcile creation with divine simplicity. Both Christianity and Platonism will appeal to this doctrine in an attempt to repudiate materialism while arguing for the intelligibility of the world. The argument traces discussions of God’s relationship to the divine ideas by considering divine exemplarism in Plato’s Timaeus, Philo of Alexandria, Clement of Alexandria, and Origen, before appraising Plotinus’ argument that the divine ideas are internal to nous and Athanasius’ claim that the Son is homoousios, or proper, to the Father. Furthermore, it is established that from their shared monotheism both Christianity and Platonism understand the divine exemplar as internal to God, resulting in single first principle.