Augustissimae Virginis Mariae §7

⁷ We do not hesitate to assign a pre-eminent place among these societies to that known as the Society of the Holy Rosary. If we regard its origin, we find it distinguished by its antiquity, for St. Dominic himself is said to have been its founder. If we estimate its privileges, we see it enriched with a vast number of them granted by the munificence of our predecessors. The form of the association, its very soul, is the Rosary of Our Lady, of the excellence of which We have elsewhere spoken at length. Still the virtue and efficacy of the Rosary appear all the greater when considered as the special office of the Sodality which bears its name. Everyone knows how necessary prayer is for all men; not that God's decrees can be changed, but, as St. Gregory says, "that men by asking may merit to receive what Almighty God bath decreed from eternity to grant them" (Dialog., lib. i., c. 8). And St. Augustine says, "He who knoweth how to pray aright, knoweth how to live aright" (In Ps. cxviii). But prayers acquire their greatest efficacy in obtaining God's assistance when offered publicly, by large numbers, constantly, and unanimously, so as to form as it were a single chorus of supplication; as those words of the Acts of the Apostles clearly declare wherein the disciples of Christ, awaiting the coming of the Holy Ghost, are said to have been "persevering with one mind in prayer" (Acts i., 14). Those who practise this manner of prayer will never fail to obtain certain fruit. Such is certainly the case with members of the Rosary Sodality. Just as by the recitation of the Divine Office, priests offer a public, constant, and most efficacious supplication; so the supplication offered by the members of this Sodality in the recitation of the Rosary, or "Psalter of Our Lady," as it has been styled by some of the Popes, is also in a way public, constant, and universal.