This book examines twentieth century theological commentators (Brath, Rahner, Florovsky, Lossky) on the problem of the doctrine of energies in God. Counter to existing trends in western theology, the author gives a positive evaluation of this doctrine and seeks common ground between the eastern idea of essence and energies and the western identification of the inner and economic trinity. Though written from a clearly western perspective, the book argues the coherenceof the eastern position, and that underlying both eastern and western positions is a common intention to say that the encounter with God is real, and that the primary ontological distinction is between God and creation. _ This book was originally presented as the author's thesis(doctoral)-Universitaet Tuebingen, 1992, under the title: Die Lehre von den ungeschaffenen Energien: Ihre Bedeutung fuer die oekumenische Theologie.