Virtually every aspect of Catholicism which is controversial within the Church or a stumbling block to non-Catholic Christians is treated in this book. Rather than avoiding what is most glaringly un-modern or what is most criticized by non-Catholics, Balthasar reviews these elements one by one, and shows how they are rooted in the central Christian mysteries and the commonly accepted tradition. What is specifically Catholic is not defended polemically, but described in such a way that others can see, even from their own point of view, the inner consistency with the mystery affirmed by all. Here is a form of thought which is truly ecumenical precisely because it is fully Catholic.