When the young combative theologian Hans Küng published his dissertation on Karl Barth's doctrine of justification in 1957, it was nothing short of an ecumenical sensation: Küng asserted nothing less than that a properly understood doctrine of the justification of man before God could unite Protestants and Catholics. Today, a shared ecumenical understanding of justification is particularly significant: In today's society, the question of justification and the freedom of a Christian is more relevant than ever. "I welcome your book as a symptom that the flood of times, in which Catholic and Protestant theologians wanted to speak either polemically against each other or in non-committal pacifism, mostly not at all, is not yet over, but at least is receding." Karl Barth to Hans Küng.