The 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 XIIIO Virgin most holy, none abounds in the knowledge of God except through thee; none, O Mother of God, obtains salvation except through thee, none receives a gift from the throne of mercy except through thee.
Pope Leo XIIIWhoso turns his attention to the bitter strifes of these days and seeks a reason for the troubles that vex public and private life must come to the conclusion that a fruitful cause of the evils which now afflict, as well as of those which threaten us, lies in this: that false conclusions concerning divine and human things, which originated in the schools of philosophy, have crept into all the orders of the state, and have been accepted by the common consent of the masses.
Pope Leo XIIIEvery man has by nature the right to possess property as his own. This is one of the chief points of distinction between man and the animal creation.
Pope Leo XIIIThe present age handed over the workers, each alone and defenseless, to the unbridled greed of competitors... so that a very few and exceedingly rich men have laid a yoke of almost slavery on the unnumbered masses of non-owning workers.
Pope Leo XIIIAs Our Predecessors have many times repeated, let no man think that he may for any reason whatsoever join the Masonic sect, if he values his Catholic name and his eternal salvation as he ought to value them. Let no one be deceived by a pretense of honesty. It may seem to some that Freemasons demand nothing that is openly contrary to religion and morality; but, as the whole principle and object of the sect lies in what is vicious and criminal, to join with these men or in any way to help them cannot be lawful
Pope Leo XIIITherefore those governing the State ought primarily to devote themselves to the service of individual groups and of the whole commonwealth, and through the entire scheme of laws and institutions to cause both public and individual well-being to develop spontaneously out of the very structure and administration of the state.
Pope Leo XIII