But the supreme teacher in the Church is the Roman Pontiff. Union of minds, therefore, requires, together with a perfect accord in the one faith, complete submission and obedience of will to the Church and to the Roman Pontiff, as to God Himself.
Pope Leo XIIITo the shepherds alone was given all power to teach, to judge, to direct; on the faithful was imposed the duty of following their teaching, of submitting with docility to their judgment, and of allowing themselves to be governed, corrected, and guided by them in the way of salvation. Thus, it is an absolute necessity for the simple faithful to submit in mind and heart to their own pastors, and for the latter to submit with them to the Head and Supreme Pastor.
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 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 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 XIIIThoughtful men, with hearts craving the truth, have come to seek in the Catholic Church the road which leads with surety to eternal life. They have understood that they could not cleave to Jesus Christ as the Head of the Church if they did not belong to the Body of Jesus Christ which is the Church. Nor could they ever hope to possess in all its purity the faith of Jesus Christ if they were to reject its legitimate teaching authority entrusted to Peter and his successors.
Pope Leo XIII