9The Second Vatican Council affirmed that it is from both Scripture and Tradition that the Church draws her certainty about all that God has revealed. This thesis examines the theologies of Tradition of Yves Congar and Joseph Ratzinger (both of whom contributed to this teaching of Dei Verbum), noting that despite many similarities, there are significant differences in their emphasis. In particular, the study argues that Ratzinger holds a strongly Christological conception of Tradition, which manifests in a sacramental notion of how Tradition operates. He also gives greater weight to the power of individual traditions to draw the believer into an experience of Christ's Revelation. Congar's theology of Tradition is more pneumatological, emphasising Tradition as the work of the Holy Spirit in bearing the Church towards the fullness of revealed truth. Congar also gives greater attention to the role of the laity in the work of Tradition and the contribution made to the understanding of Revelation by the Church's historical experiences. The comparison of these two significant twentieth century theologians can contribute to a constructive theology of Tradition for the contemporary Church.