Book excerpt: This book attempts to resolve some of the oldest and most bitter controversies between the Eastern and Western Christian churches: those concerning the doctrine of God, the nature of salvation, and theological method, all of which converge in the doctrine of deification. Deification was the dominant patristic model of salvation and remained the essential paradigm in the East but was thought to have disappeared from Western theology by the Middle Ages. A. N. Williams examines two key thinkers, each of whom is championed as the authentic spokesman of his own tradition and reviled by the other side. Taking Thomas Aquinas as representative of the West and Gregory Palamas for the East, she presents fresh readings of their work that both reinterpret each thinker and show an area of commonality between them much greater than has previously been acknowledged.