In Dietrich Bonhoeffer's Ethics the notion of reality plays a central role. The present article focuses on the ethical implications of the Chalcedonian Christology underlying this concept. This approach is tied to the debate on the relationship between the universal and specific identity of Christian social ethics in public discourse. In the opening section the article outlines the pertinence of this debate with regard to Bonhoeffer's Christological ethic. In the following section the article analyzes Bonhoeffer's concept of reality and the (...) implied Chalcedonian traits. With this foundation established the article raises the question about its social ethical implications. The final part of the article argues that Bonhoeffer's ethics and ecclesiology cannot be separated from each other, explaining why Bonhoeffer's notion of reality leads to an assertion of the church's role in letting reality become real. In the light of Bonhoeffer's notion of reality the last section argues for the reconciliation of Christian witness and participation in public discourse. (shrink)