Ubi Arcano Dei Consilio §19

¹⁹ Our letter so far has been devoted to a recital of the evils which afflict present-day society. We must now search out, with all possible care, the causes of these disorders, some of which have already been referred to. At this point, Venerable Brothers, there seems to come to Us the voice of the Divine Consoler and Physician Who, speaking of these human infirmities says: "All these evil things come from within." ( Mark vii, 23.)