Abstract: In Lutheran ethics the Chalcedonian notion of the communication of properties (communicatio idiomatum) plays an important role in understanding the paradoxical relation between the reality of God and the reality of the world. This motif also plays an important role for Martin Luther and Dietrich Bonhoeffer. In a contemporary context the Chalcedonian understanding substantiates a differentiated unity between universality and specificity with regard to the foundation of a Lutheran social ethic.