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 XIIIThe liberty of thinking and publishing whatsoever each one likes, without any hindrances, is not in itself an advantage over which society can wisely rejoice. On the contrary, it is the fountainhead and origin of many evils.
Pope Leo XIII