The paradox of Luther's Reformation -- pt. 1. Critical reverence towards tradition. Church and church history -- The meaning of tradition -- The authority of church councils -- The preservation of Catholic liturgical substance -- The Protestant principle in worship -- pt. 2. Unity despite separation. Fathers and reformers -- Negotiations toward unity -- The irenic reformer -- A reformation consensus -- pt. 3. Catholic substance and Protestant principle today. Evangelical Catholicity and contemporary Catholicism -- Catholic substance in contemporary Protestantism -- The Catholic context of Protestant theology -- Evangelical Catholicity and its theological tasks.