This article reevaluates the Lutheran theologian Dietrich Bonhoeffer’s widely criticised engagement with social theory in his doctoral dissertation Sanctorum Communio. On the one hand, it argues that there are specific theological concerns underlying Bonhoeffer’s initial decisions with respect to social theory in ways that have not been sufficiently recognized. This is the case for both Bonhoeffer’s distinction between social philosophyand sociology and his related preference for formal (rather than historical) approaches to sociology. On the other hand, this article insists that Bonhoeffer did not simply draw or rely upon formal approaches to sociology uncritically. Rather, he carefully took up and reworked concepts and insights from social theory.