21 As We recalled all these things, We humbly entreated God to return the Eastern church at long last to the bosom and embrace of Rome. Their long separation, contrary to the teachings of their ancient Fathers, keeps them miserably from this See of Peter. Irenaeus testifies (and he received the doctrine of St. John the Apostle from his master Polycarp) that "it is necessary for all to join the Church because of its greater authority, that is, all of those who are faithful." Meanwhile We received letters from the Venerable Brothers Ignatius Ephrem II Rahmani, Patriarch of Syria at Antioch; Elias Petrus Huayek, Maronite Patriarch at Antioch; and Joseph Emmanuel Thomas, Chaldean Patriarch at Babylon. They presented weighty arguments beseeching Us earnestly to bestow upon Ephrem, the Syrian Deacon of Edessa, the title and honors of Doctor of the Universal Church. In addition to these requests, a number of Cardinals, Bishops, Abbots and Generals of religious orders of the Greek and Latin rites sent their supporting petitions. We decided promptly to consider a matter so agreeable to our own desires. We recalled that these Eastern Fathers have always considered Blessed Ephrem a teacher of the truth and an inspired doctor of the Catholic Church. Nor were We unaware that his authority had great weight from the very beginning, not only with the Syrians, but also with the neighboring Chaldeans, Armenians, Maronites, and Greeks. In fact, they had each translated the writings of the Deacon of Edessa into their own languages, and read them eagerly both in liturgical celebrations and at home. Even today his songs can be found among the Slavs, Copts, Ethiopians, and even the Jacobites and Nestorians. We also recalled that the Roman Church has honored him before this. From ancient times it commemorated Blessed Ephrem in the Martyrology for February first and not without special praise for his holiness and learning. During the sixteenth century, a church was built on the Viminal hill in Rome itself to honor the Blessed Virgin and St. Ephrem. Our predecessors Gregory XIII and Benedict XIV instructed first Vossius and then Assemanus, to collect, edit, and publish the works of St. Ephrem in order to illustrate the Catholic faith and nourish the piety of the faithful. More recently, in 1909, St. Pius X approved for the Benedictine monks of the Priory of St. Benedict and Ephrem in Jerusalem, a proper mass and office in honor of this same saint and deacon of Edessa, with excerpts for the most part from the Syrian liturgy. Therefore, in order to further glorify the great anchorite, and at the same time to grat fy the Christian peoples of the East, We have sent to the Sacred Congregation of Rites a recommendation to proceed in this matter, in accordance with the prescriptions of the sacred canons and current discipline. The result was most gratifying, since the cardinals at the head of this same congregation responded through its prefect, Our Venerable Brother Anthony S.R.E. Cardinal Vico, Bishop of Portuensis and St. Rufina, that they too desired and humbly asked Us the same thing the others had asked in their suppliant letters.
Source: Principi Apostolorum Petro (Vatican.va)