Neither a recapitulation of the Catholic Church's teaching on the Filioque nor a comprehensive reconstruction of Thomas Aquinas’ theology of the Spirit, this paper is instead a response to several objections raised against Thomas’ defense of the Filioque by the highly-original Orthodox theologian Sergei Bulgakov. Following his patristic predecessors, particularly Augustine of Hippo and Cyril of Alexandria, and the conciliar tradition, Thomas situates the contemplation of the Spirit's procession within Christology—for He is the Spirit of Christ (see Rom. 8:9). The Christological framing of the Spirit's procession a Filio leavens theological examination of the doctrine's expansive influence on the understanding of other Christian Mysteries. By examining Matthias Joseph Scheeben's speculative reflections on the procession of the Spirit as analogous to the creation of Eve and illuminative of the Church as Bride of Christ, Bulgakov's most damning criticism, that the Filioque is a theologoumenon lacking in “life-significance” is rebutted. Finally, additional avenues of elaborating upon the Spirit's procession as indivisibly connected to other mysteries of the faith are advanced.