This is a study of Spirit-Christology—a contemporary theological model of the relationship between Jesus Christ and the Holy Spirit. Del Colle measures this christological model against trinitarian theology and tests its viability. He investigates in particular the development of a Roman Catholic Spirit-Christology, which has arisen from within the modern neo-scholastic theological tradition. Contrary to other interpreters, Del Colle argues that an incarnational christology and a Spirit-Christology are not conflicting but complementary and that this is recognized by the older and deeper tradition. In conclusion, he seeks to demonstrate the productivity of the Spirit-Christological model in reference to three major areas of concern for contemporary systematic theology: cultural pluralism and diversity, emancipation and social praxis, and inter-religious dialogue.