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 XIIIWith reason, then, the common opinion of mankind, little affected by the few dissentients who have contended for the opposite view, has found in the careful study of nature, and in the laws of nature, the foundations of the division of property, and the practice of all ages has consecrated the principle of private ownership, as being pre-eminently in conformity with human nature, and as conducing in the most unmistakable manner to the peace and tranquility of human existence.
Pope Leo XIIIOur Lord came to the aid of each great tribulation with a special devotion. The present and future tribulations of the Church and of nations are greater than at any other period, and this persecution is more dangerous than those of previous times. Hence, the devotion which God sends to the succor of His Church and of the nations at the present time is the devotion to the Most Holy Eucharist. It is the highest of all devotions.
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