The human race has always felt the need of a priesthood: of men, that is, who have the official charge to be mediators between God and humanity, men who should consecrate themselves entirely to this mediation, as to the very purpose of their lives, men set aside to offer to God public prayers and sacrifices in the name of human society. For human society as such is bound to offer to God public and social worship. It is bound to acknowledge in Him its Supreme Lord and first beginning, and to strive toward Him as to its last end, to give Him thanks and offer Him propitiation. In fact, priests are to be found among all peoples whose customs are known, except those compelled by violence to act against the most sacred laws of human nature. They may, indeed, be in the service of false divinities; but wherever religion is professed, wherever altars are built, there also is a priesthood surrounded by particular marks of honor and veneration. The priest, according to the magnificent definition given by St. Paul is indeed a man Ex hominibus assumptus, "taken from amongst men," yet pro hominibus constituitur in his quae sunt ad Deum, "ordained for men in the things that appertain to God": his office is not for human things, and things that pass away, however lofty and valuable these may seem; but for things divine and enduring. These eternal things may, perhaps, through ignorance, be scorned and contemned, or even attacked with diabolical fury and malice, as sad experience has often proved, and proves even today; but they always continue to hold the first place in the aspirations, individual and social, of humanity, because the human heart feels irresistibly it is made for God and is restless till it rests in Him. All the good that Christian civilization has brought into the world is due, at least radically, to the word and works of the Catholic priesthood. Such a past might, to itself, serve as sufficient guarantee for the future; but we have a still more secure guarantee, "a more firm prophetical word" in the infallible promises of Christ. (Papal Encyclical, Ad Catholici Sacerdotii, 20 December 1935).