Gregory of Nyssa is widely regarded as the most substantial thinker and theologian among the three Cappadocians and is often used as the representative of Greek trinitarian theology. Through a fresh examination of Gregory's trinitarian theology in its historical context, Michel Rene Barnes reveals the special importance of the concept of ""power""--dynamis. The book also brings to light the way in which ""power"" served as a fundamental concept in all stages of patristic trinitarian theology and shows the origins of the concept in Greek philosophy and medicine. The most important senses of ""power"" have little to do with political or physical power. Since the time of the pre-Socratics, Greek philosophy and medicine used the term to refer to the capacity of anything to be a cause. It is this sense of ""power"" that figures so substantially in the development of the doctrine of the Trinity in the patristic period. Indeed, what is recognized as the definitive form of Nicene trinitarian theology--normative for all Christians--was established in the second half of the fourth century using arguments based on an understanding of God as a cause--God as a ""power."" Nowhere is the importance of ""power"" for supporting a Nicene trinitarian theology as great and as closely argued as it is in the theology of Gregory of Nyssa. This study will be useful for those who study the development of the doctrine of the Trinity, as well as those who are interested in the role of scriptural and philosophical resources in Christian theology. Finally, the in-depth account of the importance of the philosophical use of ""power"" will be of use to scholars of ancient and hellenistic Greek philosophy.

Synopsis: Ralph del Colle was born in New York City on October 3, 1954 and was raised in Mineola, Long Island. He attended Xavier High School in Chelsea and received a BA in History and Literature of Religions from New York University, and MDiv, MPhil, and PhD degrees from Union Theological Seminary. Ralph taught for 17 years in the Marquette University Theology Department; prior to that he taught at Barry University, Miami Shores, Florida and at St. Anselm College, Manchester, New Hampshire. Ralph's lively Christian faith and interest in church unity led to his participation in ecumenical dialogues. He served as a representative to the International Catholic-Pentecostal Dialogue for the Pontifical Council on Christian Unity for 12 years and also served on the Catholic-Reformed Dialogue and Catholic-Evangelical Dialogue, both for the U.S. Conference of Catholic Bishops. He was invited by the Pontifical Council to serve as a representative to the World Council of Churches Assembly in Harare, Zimbabwe in 1998. In 2002-2003, he served as the President of the Society for Pentecostal Studies and in 2003 Ralph received the Archbishop's Vatican II Award. Ralph's scholarly work, especially his work on the Holy Spirit, made significant contributions to the field of Systematic Theology. Ralph died in July of 2012, slightly more than four weeks after he was diagnosed with a rare form of liver cancer. He was fifty-seven. Author Biography: Michel Rene Barnes is Associate Professor for Patristics at Marquette University. He has written extensively on the trinitarian theologies of Augustine and Gregory of Nyssa. His most recent publication, "Ebion at the Barricades: Moral Narrative and Post-Christian Catholic Theology," is a radical critique of Catholic Systematic theology as it has been practiced since Vatican Two. CONTRIBUTORS: Michel Rene Barnes, Richard J. Barry, Peter J. Casarella, David M. Coffey, D. Lyle Dabney, The Reverend Andrew Grosso, Paul R. Hinlicky, D. Thomas Hughson, Ulrich L. Lehner, Matthew Levering, D. Stephen Long, Bruce D. Marshall, Mickey L. Mattox, Rodrigo J. Morales, Joseph G. Mueller, S.J., C. C. Pecknold, R. R. Reno, Philip J. Rossi, S.J, James K. A. Smith, Geoffrey Wainwright, John Webster, Thomas G. Weinandy, O.F.M.