Ubi Arcano Dei Consilio §13

¹³ It is most sad to see how this revolutionary spirit has penetrated into that sanctuary of peace and love, the family, the original nucleus of human society. In the family these evil seeds of dissension, which were sown long ago, have recently been spread about more and more by the fact of the absence of fathers and sons from the family fireside during the War and by the greatly increased freedom in matters of morality which followed on it as one of its effects. Frequently we behold sons alienated from their fathers, brothers quarreling with brothers, masters with servants, servants with masters. Too often likewise have we seen both the sanctity of the marriage tie and the duties to God and to humankind, which this tie imposes upon men, forgotten.