For what concerns diversity of rites in the sacred liturgy, the Apostolic See has always made its position clear: not only it does not condemn diversity, but it eagerly and willingly grants to each nation the right to keep and preserve the legitimate customs and traditions of its forbears.
Pope Leo XIIIIt is shameful and inhuman to treat men like chattels to make money by, or to regard them merely as so much muscle or physical power.
Pope Leo XIIIThe empire of Christ the King includes not only Catholic nations, not only baptized persons who, though of right belonging to the Church, have been led astray by error, or have been cut off from her by schism, but also all those who are outside the Christian faith: so that truly the whole of mankind is subject to the power of Jesus Christ.
Pope Leo XIIIOnce the demands of necessity and propriety have been met, the rest that one owns belongs to the poor.
Pope Leo XIIIIt must be assumed and established as a principle, that the right of private property must be regarded as sacred. Wherefore, the law ought to favor this right and, so far as it can, see that the largest possible number among the masses of the population prefer to own property.... But if the productive activity of the multitude can be stimulated by the hope of acquiring some property... , it will gradually come to pass that, with the difference between extreme wealth and extreme penury removed, one class will become the neighbor to the other.
Pope Leo XIIINot only, in strict truth, was marriage instituted for the propagation of the human race, but also that the lives of husbands and wives might be made better and happier. This comes about in many ways: by their lightening each other's burdens through mutual help; by constant and faithful love; by having all their possessions in common; and by the heavenly grace which flows from the sacrament.
Pope Leo XIII