The death sentence is a necessary and efficacious means for the Church to attain its end when rebels act against it and disturbers of the ecclesiastical unity, especially obstinate heretics and heresiarchs, cannot be restrained by any other penalty from continuing to derange the ecclesiastical order and impelling others to all sorts of crime ... When the perversity of one or several is calculated to bring about the ruin of many of its children it is bound effectively to remove it, in such wise that if there be no other remedy for saving its people it can and must put these wicked men to death.
Pope Leo XIIINothing emboldens the wicked so greatly as the lack of courage on the part of the good.
Pope Leo XIIITo this must be added that the hiring of labor and the conduct of trade are concentrated in the hands of comparatively few; so that a small number of very rich men have been able to lay upon the teeming masses of the laboring poor a yoke little better than that of slavery itself.
Pope Leo XIIIBut the supreme teacher in the Church is the Roman Pontiff. Union of minds, therefore, requires, together with a perfect accord in the one faith, complete submission and obedience of will to the Church and to the Roman Pontiff, as to God Himself.
Pope Leo XIIIAll Catholics must make themselves felt as active elements in daily political life in the countries where they live. They must penetrate, wherever possible, in the administration of civil affairs; must constantly exert the utmost vigilance and energy to prevent the usages of liberty from going beyond the limits fixed by God's law. All Catholics should do all in their power to cause the constitutions of states and legislation to be modeled on the principles of the true Church.
Pope Leo XIII