Spirit Christology has emerged as an important focus in recent theology. It offers new perspectives on Christology and Pneumatology. Can these new perspectives lead to advances in trinitarian theology itself? The classical theologies of both East and West tended to express great reserve about moving too easily from the economy of salvation to ideas about God in se. In the twentieth century, Karl Rahner s argument that the economic Trinity is the immanent Trinity and vice versa helped lead to a significant erosion of this reserve, though not without controversy. The work of David Coffey...