Pope Benedict XVI, since his election to the papacy, has urged Catholic clergy and theologians to interpret the documents of the second Vatican Council using a "hermeneutic of continuity." This thesis seeks to answer whether such a hermeneutic is possible by focusing on one aspect of the Dogmatic Constitution on the Church, Lumen Gentium. The methodology here employed is a critical analysis of one of the major patristic sources of Lumen Gentiums teaching, St. Augustine of Hippo. In claiming St. Augustines support for its doctrine, Lumen Gentium also offers an interpretation of his thought. For Lumen Gentiums teaching to be plausible, we must be able to conclude that Augustines teaching is essentially identical to it. In that connection, Lumen Gentiums claim that the Church is both a spiritual and visible reality forces us to consider a controverted topic in Augustinian studies: can Augustines city of God be identified with the hierarchical Church? In order to resolve that question, we will examine both the historical and eschatological aspects of the Church in Augustines thought, with some reference (treated in an appendix) to the compatibility between his theory of predestination and his ecclesiology. Further, what the Council meant when it said that the Church of Christ subsists in the Catholic Church, and whether this change in terminology, along with its implications in the field of ecumenism, can be reconciled with St. Augustines ecclesiology must be determined with a view to establishing the continuity between pre and post conciliar Catholic ecclesiology. St. Augustine developed his understanding of the nature of the Church in the early years of his ecclesiastical career through his polemical battles with the Donatist schismatics, and so the history of that schism is related in an appendix.

Pope Benedict XVI, since his election to the papacy, has urged Catholic clergy and theologians to interpret the documents of the second Vatican Council using a "hermeneutic of continuity." This thesis seeks to answer whether such a hermeneutic is possible by focusing on one aspect of the Dogmatic Constitution on the Church, Lumen Gentium. The methodology here employed is a critical analysis of one of the major patristic sources of Lumen Gentiums teaching, St. Augustine of Hippo. In claiming St. Augustines support for its doctrine, Lumen Gentium also offers an interpretation of his thought. For Lumen Gentiums teaching to be plausible, we must be able to conclude that Augustines teaching is essentially identical to it. In that connection, Lumen Gentiums claim that the Church is both a spiritual and visible reality forces us to consider a controverted topic in Augustinian studies: can Augustines city of God be identified with the hierarchical Church? In order to resolve that question, we will examine both the historical and eschatological aspects of the Church in Augustines thought, with some reference (treated in an appendix) to the compatibility between his theory of predestination and his ecclesiology. Further, what the Council meant when it said that the Church of Christ subsists in the Catholic Church, and whether this change in terminology, along with its implications in the field of ecumenism, can be reconciled with St. Augustines ecclesiology must be determined with a view to establishing the continuity between pre and post conciliar Catholic ecclesiology. St. Augustine developed his understanding of the nature of the Church in the early years of his ecclesiastical career through his polemical battles with the Donatist schismatics, and so the history of that schism is related in an appendix.