The momentous encounter between Christian thought and Greek philosophy reached a high point in fourth-century Byzantium, and the principal actors were four Greek-speaking Christian thinkers from Cappadocia: Basil of Caesarea, Gregory of Nazianzus, Gregory of Nyssa, and Macrina, the sister of Basil and Gregory of Nyssa. The author examines the writings of the Cappadocians looking for both the encounter and the synthesis between Christianity and Hellenism. This study is based upon the 1992-1993 Gifford Lectures on Natural Theology at the University of Aberdeen. The author used the lectureship as an opportunity to address, head-on and at length, the perennial issue of the Christian encounter with Hellenism, because that has been the historical matrix for the very idea of 'natural theology.'