The first law of history is to dread uttering a falsehood; the next is not to fear stating the truth; lastly, the historian's writings should be open to no suspicion of partiality or animosity.
Pope Leo XIIIThe sacred rites, although not instituted specifically for proving the truth of the dogmas of the Catholic Faith incontrovertibly, are effectively the living voice of Catholic Truth, the oft-sounded expression of it. For that very reason the true Church of Christ, even as she shows great zeal to guard inviolate those forms of divine worship - since they are hallowed and are not to be changed - sometimes grants or permits something novel in the performance of them in certain instances. This she does especially when they are in conformity with their venerable antiquity.
Pope Leo XIIIIf unbridled licence of speech and writing be granted to all, nothing will remain sacred and inviolate; even the highest and truest mandates of nature, justly held to be the common and noblest heritage of the human race, will not be spared. Thus, truth being gradually obscured by darkness, pernicious and manifold error, as too often happens, will easily prevail.
Pope Leo XIIIThe 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 XIII