Diuturnum §3

³ These perils to commonwealth, which are before Our eyes, fill Us with grave anxiety, when We behold the security of rulers and the tranquility of empires, together with the safety of nations, put in peril almost from hour to hour. Nevertheless, the divine power of the Christian religion has given birth to excellent principles of stability and order for the State, while at the same time it has penetrated into the customs and institutions of States. And of this power not the least nor last fruit is a just and wise proportion of mutual rights and duties in both princes and peoples. For in the precepts and example of Christ our Lord there is a wonderful force for restraining in their duty as much those who obey as those who rule; and for keeping between them that agreement which is most according to nature, and that concord of wills, so to speak, from which arises a course of administration tranquil and free from all disturbance. Wherefore, being, by the favor of God, entrusted with the government of the Catholic Church, and made guardian and interpreter of the doctrines of Christ, We judge that it belongs to Our jurisdiction, venerable brethren, publicly to set forth what Catholic truth demands of every one in this sphere of duty; thus making clear also by what way and by what means measures may be taken for the public safety in so critical a state of affairs.