More than a decade ago, I wrote a book called Reinhold Niebuhr and Christian Realism. The distinction between the man and the method was important to me, as it was to Niebuhr himself. Christian realism did not belong to him alone, though he was its most articulate and influential voice. It is a way of thinking deeply embedded in Christian tradition, and it can be systematically distinguished from other ways of thinking about politics, ethics, and theology available in Niebuhr's time and in ours.

This volume continues that effort to take the way of thinking that Niebuhr represented beyond his own formulation of it. This is not because I think less of Niebuhr, but precisely because I think his Christian realism has been intellectually isolated by more recent developments in philosophy and theology that make it harder for contemporary scholars to appreciate his insights. I have tried to address these problems here by emphasizing the social and political pluralism in the Christian realist tradition and by stressing the theology of responsibility on which his pragmatic approach to moral problems depends. The idea of responsible action connects Niebuhr more closely than I had understood before to his theological adversary, Karl Barth, and to his erstwhile student, Dietrich Bonhoeffer. This book is in some respects an effort to write the theology and ethics we might have had if Niebuhr and Bonhoeffer had each had the opportunity to actually understand what the other was saying.