"Libertas Ecclesiae . . .

. . .  If in any pair of words, then surely in this one are embraced the greatest and profoundest motifs of human community life.  For many centuries these words formed the headlines over the most exciting chapters of political history, stirred generation after generation before which this same problem was put and is put anew today.  The eras of political history are, indeed, distinguished according to their attempts, successes, and failures in finding their answers to this problem.  For, what matters here is not a couple of abstract concepts.  What matters here is not religion as a completely private affair of isolated individuals secluded from public life.  What matters here is the Una Sancta , Christ living in and through a history that counts its periods of years before and after His birth."

Heinrich A. Rommen, The State in Catholic Thought (1945).