2 We, indeed, to all men are the Vicar of Christ, the Son of God, who so loved the human race that not only did He not refuse, taking our nature to Himself, to live among men, but delighted in bearing the name of the Son of Man, openly proclaiming that He had come upon earth "to preach deliverance to the captives"(1) in order that, rescuing mankind from the worst slavery, which is the slavery of sin, "he might re-establish all things that are in heaven and on earth,"(2) and so bring back all the children of Adam from the depths of the ruin of the common fall to their original dignity. The words of St. Gregory the Great are very applicable here: "Since our Redeemer, the Author of all life, deigned to take human flesh, that by the power of His Godhood the chains by which we were held in bondage being broken, He might restore us to our first state of liberty, it is most fitting that men by the concession of manumission should restore to the freedom in which they were born those whom nature sent free into the world, but who have been condemned to the yoke of slavery by the law of nations."(3) It is right, therefore, and obviously in keeping with Our apostolic office, that We should favor and advance by every means in Our power whatever helps to secure for men, whether as individuals or as communities, safeguards against the many miseries, which, like the fruits of an evil tree, have sprung from the sin of our first parents; and such safeguards, of whatever kind they may be, help not only to promote civilization and the amenities of life, but lead on to that universal restitution of all things which our Redeemer Jesus Christ contemplated and desired.
Source: In Plurimis (Vatican.va)