It is quite legitimate for nations to treat those differences as a sacred inheritance and guard them at all costs. The Church aims at unity, a unity determined and kept alive by that supernatural love which should be actuating everybody; she does not aim at a uniformity which would only be external in its effects and would cramp the natural tendencies of the nations concerned. Every nation has its own genius, its own qualities, springing from the hidden roots of its being. The wise development, the encouragement within limits, of that genius, those qualities, does no harm; and if a nation cares to take precautions, to lay down rules, for that end, it has the Church's approval. She is mother enough to befriend such projects with her prayers provided that they are not opposed to the duties incumbent on men from their common origin and shared destiny. (Papal Encyclical, Mater et Magistra, 15 May 1961)