3 Nor can it be believed that Our words are inspired by sentiments of aversion to the new form of government or other purely political changes which recently have transpired in Spain. Universally known is the fact that the Catholic Church is never bound to one form of government more than to another, provided the Divine rights of God and of Christian consciences are safe. She does not find any difficulty in adapting herself to various civil institutions, be they monarchic or republican, aristocratic or democratic. Speaking only of recent facts, evident proof of this lies in the numerous Concordats and agreements concluded in later years, and in the diplomatic relations the Holy See has established with different States in which, following the Great War, monarchic governments were succeeded by republican forms. Nor have these new republics ever had to suffer in their institutions and just aspirations toward national grandeur and welfare through their friendly relations with the Holy See, or through their disposition, in a spirit of reciprocal confidence, to conclude conventions on subjects relating to Church and State, in conformity with changed conditions and times. Nay, We can with certainty affirm that from these trustful understandings with the Church the States themselves have derived remarkable advantages, since it is known no more effective dyke can be opposed to an inundation of social disorders than the Church, which is the greatest educator of the people and always knows how to unite, in fecund agreement, the principle of legitimate liberty with that of authority, the exigencies of justice with welfare and peace.
Source: Dilectissima Nobis (Vatican.va)