David Coffey considers the full range of issues surrounding the Trinity, one of the central doctrines of Christian faith. He looks at these issues in historical and ecumenical context, with the goal of arriving at a balanced vision that incorporates the insights of both the Western and Eastern churches. In particular, he keeps in sight both the immanent aspect of the Trinity (the Godhead considered in itself) and the Trinity's economic aspect (its role within the economy of salvation). He also suggests a way to resolve the ecumenical problem of Filioquism vs. Monopatrism -- the issue that has divided East from West for nearly a millennium.