The word priest (Germ. Priester; Fr. prêtre; Ital. prete) is derived from the Greek presbyteros (the elder, as distinguished from neoteros, the younger), and is, in the hieratical sense, equivalent to the Latin sacerdos, the Greek iereus, and the Hebrew kahane. By the term is meant a (male) person called to the immediate service of the Deity and authorized to hold public worship, especially to offer sacrifice. In many instances the priest is the religious mediator between God (gods) and man and the appointed teacher of religious truths, especially when these include esoteric doctrines. To apply the word priest to the magicians, prophets, and medicine-men of the religions of primitive peoples is a misuse of the term. The essential correlative of priesthood is sacrifice, consequently, mere leaders in the public prayers or guardians of shrines have no claim to the title priest.
Passing entirely over the supernatural blessings derived by mankind from the prayers of the priesthood, the celebration of the Holy Sacrifice, and the administration of the sacraments, secular civilization, which, through the Catholic priesthood, has spread to all nations and brought into full bloom religion, morality, science, art, and industry. If religion in general is the mother of all culture, Christianity must be acknowledged as the source, measure, and nursery of all true civilization. The Church, the oldest and most successful teacher of mankind, has in each century done pioneer service in all departments of culture. Through her organs, the priests and especially the members of the religious orders, she carried the light of Faith to all lands, banished the darkness of paganism, and with the Gospel brought the blessings of Christian morality and education. What would have become of the countries about the Mediterranean during the epoch of the migration of the nations (from 375) if the popes, bishops, and clergy had not tamed the German hordes, converted them from Arianism to Catholicism, and out of barbarism evolved order? What Ireland owes to St. Patrick, England owes to St. Augustine, who, sent by Pope Gregory the Great, brought not only the Gospel, but also a higher morality and culture. While the light of Christianity thus burned brightly in Ireland and Britain, part of Germany was still shrouded in the darkness of paganism. Bands of missionaries from the Island of Saints now brought to the continent the message of salvation and established new centres of culture. Charlemagne's great work of uniting all the German tribes into an empire was only the glorious fruit of the seed sown by St. Boniface of Certon (d. 755) on German soil and watered with the blood of martyrs. The Church of the Middle Ages, having now attained to power, continued through her priests to propagate the Gospel in pagan lands. It was missionaries who first brought to Europe news of the existence of China. In 1246 three Franciscans, commissioned by the pope, appeared in audience before the emperor of the Mongols; in 1306 the first Christian church was built in Peking. From the Volga to the Desert of Gobi, the Franciscans and Dominicans covered the land with their missionary stations. In the sixteenth century the zeal of the older orders was rivalled by the Jesuits, among whom St. Francis Xavier must be accorded a place of honour; their achievements in the Reductions of Paraguay are as incontestable as their great services in the United States. As for the French colonies in America, the American historian Bancroft declares that no notable city was founded, no river explored, no cape circumnavigated, without a Jesuit showing the way. Even if Buckle's one-sided statement were true, viz. that culture is not the result of religion, but vice versa, we could point to the work of Catholic missionaries, who are striving to lift the savages in pagan lands to a higher state of morality and civilization, and thence to transform them into decent Christians.