This groundbreaking book on trinitarian Christology addresses two major concerns. (1) Christology must be trinitarian insofar as it addresses and advocates a more active role of the Holy Spirit as a person, a role that is both singular and proper. This includes both the economic activity of the triune life in creation and the dynamic, perichoretic interactive life of God as God. (2) Christology must be ecumenical insofar as it addresses the concerns of both East and West with regard to the filioque. While it is important ecumenically to return to the original Creed of 381, the theological issues that have developed over the centuries cannot be avoided or circumvented. The question finally is whether East and West can come to a convergence of views. Thus the author sets the Eastern views of Vladimir Lossky and John Zizioulas in dialogue with three Western approaches Jürgen Moltmann, David Coffey, and Thomas Weinandy who seek creatively to develop insights that are potentially compatible with the Eastern viewpoint. The aim is to promote ecumenical dialogue that can transcend the differences occasioned by the filioque and to seek a higher ecumenical unity based in a renewed emphasis on the activity of the Holy Spirit.Michael L. Cook, SJ