This is a major work on the theology of Joseph Ratzinger by a highly regarded German theologian, priest and writer. Since his election to the Papacy, Ratzinger's theology, and in particular his ecclesiology (theology of the Church), has been in the limelight of theological and ecumenical discussions. This work studies in detail Ratzinger's ecclesiology in the light of Vatican II, against the ongoing debate about what Vatican II really meant to say about the life of the Church, its liturgy, its worship, its doctirne, its pastoral mission, and more.