Han sammenkaldte det Andet Vatikanråd der udfærdigede en encyklika, der ville ryste den katolske verden. De hed "Pacem In Terris", "Fred På Jorden".
He called to gather the 2nd Vatican council which issued a new encyclical that shook up the catholic world that was called Pacem in Terris peace on earth and ushered in a change in thinking particulary in latin america where its priests, nuns and lay persons took the