Encyclical Letter of Pope Benedict XV on St. Ephrem, the Syrian, written in 1920. The Latin title is Principi Apostolorum Petro.
To the Patriarchs, Primates, Archbishops, Bishops, and other ordinaries in peace and communion withe the Apostolic See. Cenerable Brothers, Greetings and The Apostolic Benediction.
1. To Peter the Prince of the Apostles, the divine Founder of the Church allotted the gifts of inerrancy  in matters of faith and of union with God. This relationship is similar to that of a “Choir Director of the Choir of the Apostles.” He is the common teacher and rector  of all, so that he might feed the flock of Him who established His Church  on the authority of Peter himself and his successors. And on this mystical rock the foundation  of the entire ecclesiastical structure stands firm as on a hinge. From it rises the unity of Christian charity as well as our Christian faith.
2. Indeed the unique gift of Peter’s primacy is that he might spread everywhere and preserve the riches of charity and faith, as Ignatius Theophorus, a man of Apostolic times, beautifully declared. For in those noble letters he wrote to the Roman Church on his journey, announcing his arrival in Rome to be martyred for Christ, he gave testimony to the primacy of that Church over all others by calling it ‘presiding officer over the universal community of charity.” This was to signify not only that the Universal Church was the visible image of divine charity, but also that Blessed Peter, together with his primacy and his love for Christ (affirmed by his triple confession), remains heir of the Roman See. Accordingly the souls of all the faithful should be ignited by the same fire.
3. The ancient Fathers, especially those who held the more illustrious chairs of the East, since they accepted these privileges as proper to the pontifical authority, took refuge in the Apostolic See whenever heresy or internal strife troubled them. For it alone promised safety in extreme crises. Basil the Great  did so, as did the renowned defender of the Nicene Creed, Athanasius, as well as John Chrysostom. For these inspired Fathers of the orthodox faith appealed from the councils of bishops to the supreme judgement of the Roman Pontiffs according to the prescriptions  of the ecclesiastical Canons. Who can say that they were wanting in conformity to the command which they had from Christ? Indeed, lest they should prove faithless in their duty, some went fearlessly into exile, as did Librius and Silverius and Martinus. Others pleaded vigorously for the cause of the orthodox faith and for its defenders who had appealed to the Pope, or to vindicate the memory of those who had died. Innocent I  is an example. He commanded the bishops of the East to insert the name of St. John Chrysostom in the liturgical list of the orthodox Fathers to be mentioned at mass.
4. However We, who embrace the Eastern Church with no less solicitude and charity than our predecessors, truly rejoice, now that the frightful war is ended. We rejoice that many in the Eastern community have achieved liberty and wrested their holy things from the control of the laity. They are now striving to set the nation in order, consistent with the character of its people and the established customs of their ancestors. We propose, appropriately, a splendid example of sanctity, learning, and paternal love for them to diligently imitate and nurture. We speak of St. Ephrem the Syrian, whom Gregory of Nyssa compared to the River Euphrates because he “irrigated by his waters the Christian community to bring forth fruits of faith a hundred-fold.” We speak of Ephrem, whom all the inspired orthodox Fathers and Doctors, including Basil, Chrysostom, Jerome, Francis of Sales, and Alphonsus Liguori, praise. We are pleased to join these heralds of truth, who though separated from each other in talent, in time and place, nevertheless perfect a harmony modulated by “one and the same spirit.”
5. This letter follows so shortly after Our Encyclical marking the fifteenth centenary of the birth of St. Jerome because these two illustrious men have much in common. They are almost contemporary, both were monks, both lived in Syria, and both were outstanding for their study and knowledge of the Scriptures. You may rightly compare them to “two shining lights,” one illuminating the West, the other the East. Their writings, being of the same spirit, are equally valuable. Both the Latin and the Eastern Fathers have agreed with those two and praise them similarly.
6. The birthplace of Blessed Ephrem could have been Nisibi or Edessa. What is certain is that he was connected by blood with the martyrs of the last persecution. His parents brought him up as a Christian. If they did not have the comforts of a wealthy life, they had the far greater and more splendid distinction that “they had professed Christ in judgment.” In his youth Ephrem, as he bewails in his little book of confessions, was languid and remiss in resisting the temptations by which that age is usually troubled. He was hot tempered, easily angered, quarrelsome, and unrestrained in mind and language. But while in prison on a false charge, he began to despise human things and the empty joys of this world. Therefore, as soon as he was exonerated, Ephrem at once put on the habit of a monk and ever after devoted himself completely to the exercises of piety and to the study of the Sacred Scriptures. James, the bishop of Nisibi, one of the three hundred eighteen Fathers of the Nicene Council, who had established a renowned school of exegesis in the episcopal city, became his patron. He not only fulfilled James’ expectations with his diligent and sharp-witted commentaries on the Bible, but even surpassed them. As a result, he soon became the greatest of all commentators of that school, earning the title Doctor of the Syrians. Soon he had to interrupt his study of Sacred Literature because Persian troops threatened the city. He urged on the citizens in their vigorous resistance to the Persians. With the aid of the prayers of James the bishop, they were defeated; however, after his death, the Persians again besieged the city. This time, in 363, it did fall. Because Ephrem preferred exile to serving infidels, he migrated to Edessa. There he diligently exercised the duties of an ecclesiastical doctor.
7. The house on a suburban hill where he lived soon resembled an illustrious academy with a great concourse of men eager to study the divine books. To it came learned interpreters and students of Scripture, including Zenobius, Maraba, and St. Isaac of Amidea, who acquired the title Great  because of the profusion and importance of his writings. Because of his learning and holiness, Ephrem’s fame spread from that retreat. Thus when he traveled to Caesarea to see Basil the Great, Basil, learning of his approach by divine revelation, received him reverently and spoke with him about divine concerns. According to report, it was at this time that Basil consecrated Ephrem deacon.
8. Ephrem never left his solitude in Edessa except on fixed days to preach. In his preaching, he defended the dogmas of faith from swelling heresies. If, conscious of his lowliness, he did not dare to rise to the priesthood, he nevertheless showed himself a most perfect imitator of St. Stephen in the lower rank of the diaconate. He devoted all of his time to teaching Scripture, to preaching, and to instructing the nuns in sacred psalmody. Daily he wrote commentaries on the Bible to illustrate the orthodox faith; he came to the aid of his fellow citizens, especially the poor and the stricken. What he sought to teach others, he first did absolutely and perfectly. In this way, he could serve as the example which Ignatius Theophorus proposes to the deacons when he calls them “charges of Christ” and asserts that they express “the mystery of faith in a pure conscience.”
9. How great and how active was the charity he showed his brethren in a time of famine, even though by then he was worn out by age and labor! He left the house where for so many years he had lived a heavenly rather than a human life and ran to Edessa. By that eloquence which Gregory of Nyssa characterized “as a key fashioned by divinity,” to open the minds and the coffers of the wealthy, he castigated those who were hoarding grain and vehemently demanded that they feed the poor from their surplus. And they were touched not so much by the hunger of the citizens, as by the sincerity of Ephrem. With the money he begged, he himself provided beds for those tortured by starvation and spread them in the porticos of Edessa. There he nursed the sick and met the pilgrims who came to the city from round about looking for bread. Truly this man was placed there by divine providence to aid his country! And he did not return to solitude until the next harvest provided abundance.
10. The testament he left for his fellow citizens – memorable for its faith, humility, and singular patriotism – reads as follows. “I, Ephrem, am dying. With fear, but also with reverence, I entreat you, citizens of Edessa, not to bury me under the altar or elsewhere in the house of God. It is not fitting that a worm teeming with corruption be buried in the temple and sanctuary of God. But lay me out in the tunic and mantle which I used and wore daily. Accompany me with psalms and prayers. I had neither pouch nor staff, neither wallet nor silver and gold; nor did I ever acquire or possess anything else earthly. Work diligently at my precepts and doctrines; as my disciples, do not fall away from the Catholic faith. With regard to the faith, be especially constant. Guard against adversaries – I mean evildoers, boasters, and tempters to sin. And may your city be blessed; for Edessa is the city and mother of the wise.” And so Ephrem died, but his memory lives on, to the blessing of the Church Universal. Therefore when his name began to be mentioned in the sacred liturgy, Gregory of Nyssa could say: “The splendor of his doctrine and life illumined all the earth, for he is known in almost every place where the sun shines.”
11. There is no reason to list his many writings. “He is said to have written three thousand myriad poems if one counts them all together.” His writings cover almost all ecclesiastical doctrines. There are extant commentaries on Sacred Scripture and the mysteries of the faith; sermons on obligations and on the interior life; studies on the sacred liturgy; hymns for the feastdays of our Lord and of the Blessed Virgin and of the saints, for the processions of prayers and penitential days, for the funerals of the departed. In all of these, his purity of soul shines forth as a “burning and shining” evangelical lamp. By illustrating the truth he makes us love and embrace it. Indeed when Jerome testifies about the writings of Ephrem in his day, he tells us that they were read in public liturgical assemblies along with the works of the orthodox Fathers and Doctors. He also affirms that he recognized “the sublimity of Ephrem’s genius even in the translations” of these same works from the Syrian into Greek.
12. It is indeed fitting to honor the blessed deacon of Edessa for his desire that the preaching of the divine word and the training of his disciples rest on the purity of Sacred Scripture. He also acquired honor as a Christian musician and poet. He was so accomplished in both arts that he was called the “lyre of the Holy Spirit.” From this, Venerable Brothers, you can learn what arts promote the knowledge of sacred things. Ephrem lived among people whose nature was attracted by the sweetness of poetry and music. The heretics of the second century after Christ used these same allurements to skillfully disseminate their errors. Therefore Ephrem, like youthful David killing the giant Goliath with his own sword, opposed art with art and clothed Catholic doctrine in melody and rhythm. These he diligently taught to boys and girls, so that eventually all the people learned them. In this fashion he not only renewed the education of the faithful in Christian doctrine and supported their piety with the spirit of the sacred liturgy, but also happily kept creeping heresy at bay.
13. The artistry introduced by Blessed Ephrem added dignity to sacred matters as Theodoretus stresses. The metric rhythm, which our saint popularized, was widely propagated both among the Greeks and the Latins. Indeed does it seem probable that the liturgical antiphonary with its songs and processions, introduced at Constantinople  in the works of Chrysostom and at Milan  by Ambrose (whence it spread throughout all of Italy), was the work of some other author? For the “custom of Eastern rhythm” deeply moved the catechumen Augustine in northern Italy; Gregory the Great improved it and we use it in a more advanced form. Critics acknowledge that that “same Eastern rhythm” had it origins in Ephrem’s Syrian antiphonary.
14. It is no wonder then that many of the Fathers of the Church stress the authority of St. Ephrem. Nyssenus says of his writings, “Studying the Old and New Scriptures most thoroughly, he interpreted them accurately, word for word; and what was hidden and concealed, from the very creation of the world to the last book of grace, he illumined with commentaries, using the light of the Spirit.” And Chrysostom: “The great Ephrem [is] scourge of the slothful, consoler of the afflicted, educator, instructor and exhorter of youth, mirror of monks, leader of penitents, goad and sting of heretics, reservoir of virtues, and the home and lodging of the Holy Spirit.” Certainly nothing greater can be said in praise of a man who, however, seemed so small in his own eyes that he claimed to be the least of all and a most vile sinner.”
15. Therefore, God, who has “exalted the humble,” bestows great glory on blessed Ephrem and proposes him to this age as a doctor of heavenly wisdom and an example of the choicest virtues. And the appropriateness of his example is truly singular today. The frightful war is over and there is something of a new order for many nations, especially in the East. We, along with you and all good men, must endeavor to restore in Christ whatever remains of human and civil culture and to recall the erring society of men to God and to His Holy Church. Though our ancestors’ institutions failed, public affairs are in tumult, and everything human is confused, the Catholic Church alone never vacilates, but instead looks confidently to the future. She alone is born for immortality, trusting in the words addressed to Blessed Peter: “Upon this rock I will build my Church and the gates of hell will not prevail against her.”
16. Would that other ecclesiastical teachers learn from him how skilfully, how diligently they must work in preaching the doctrine of Christ! And indeed the piety of the faithful has nothing stable and advantageous except to adhere entirely to the mysteries and precepts of the faith. Those who legitimately teach the Sacred Scriptures are warned by the example of the Edessine not to distort the Sacred Scriptures to the good pleasure of their own inclinations, nor, in investigating them, to depart a finger’s breadth from the constant interpretation of the Church. “No prophecy of Scripture originates from private interpretation. For never by will of man was prophecy brought forth. But holy men of God spoke as they were moved by the Holy Spirit.” And that Spirit who has spoken to men by the prophets is the same one who for the Apostles “opened their minds that they might understand the Scriptures” and the same who constituted his Church to announce, interpret, and preserve revelation, so that it might be “the pillar and mainstay of truth.”
17. Let honorable men, in the tradition of Ephrem – We mean the illustrious offspring of the monastic orders – preserve the dignity which arose with Anthony and Basil in the East. This was propagated later by offshoots in the West, and in many ways has been noteworthy for the Christian community. Therefore may these seekers of Evangelical perfection never cease to look up to and imitate the anchorite of Edessa. For a monk will profit the Church most when he exemplifies what his habit signifies to God and men, that is, according to a saying of the ancient Fathers of the East, he must be “a son of the covenant,” and again “an Angel whose mission is mercy, peace, and the sacrifice of praise,” as the blessed Nilus the Younger beautifully defines him.
18. Finally, Venerable Brothers, all who are your subjects, both clergy and people, may learn this from Blessed Ephrem: the love of the fatherland, whose claims indeed rest on the profession of Christian wisdom itself, must not be separated from the love of the heavenly fatherland, nor be preferred to it. We speak of that fatherland which is nothing other than the innermost rule of God in the souls of the just, begun here, then perfected in heaven. Indeed the Catholic Church exhibits a mystical image of this, since, transcending all differences of nationality and language, she embraces all sons of the Lord as a single family under a common father and pastor. Ephrem also teaches that the sources of spiritual life are in the sacraments, in the observance of the Evangelical precepts, and in the manifold exercises of piety which the liturgy supplies and the authority of the Church proposes. On this subject, note what our saint has to say about the sacrifice of the Altar: “With his hands the priest places Christ on the altar to become food. He addresses the Father as a member of the family saying, “Give me your Spirit, that in his coming he may descend upon the altar and sanctify the bread placed there to become the Body of your only begotten Son. He tells him of Christ’s passion and death and exposes His blows; nor is His divinity ashamed of those blows. He says to the invisible Father: behold, your Son is nailed to the cross, his garments are sprinkled with blood, his side pierced with a lance. He recalls for him the passion and death of his Beloved, as though he had forgotten them, and the Father, hearing, favors his request.” He also remarks on the state of the just after death. In a singular manner, these remarks augment the constant doctrine of the Church, later defined in the council of Florence. “The deceased has been taken away by the Lord and has already been introduced to the kingdom of heaven. The soul of the deceased is received in heaven and inserted as a pearl in the crown of Christ. The deceased even now resides with God and his saints.”
19. Regarding his devotion to the Virgin Mother of God, who can say enough? “You, O Lord and your Mother” he says in a Nisibean poem, “are the only ones who are in all respects perfect beauty; in you, my Lord, there is no stain, nor in your Mother is there any dishonor.” “The lyre of the Holy Spirit” never sounded sweeter than when he was asked to sing the praises of Mary or to celebrate her perfect virginity, her divine maternity, or her full patronage of mercy toward man.
20. Nor is he less zealous when, from faraway Edessa, he looks to Rome to extol the Primacy of Peter: “Hail, holy kings, Apostles of Christ,” and to the choir of Apostles, “Hail, light of the world…. Christ is the light and the lampstand is Peter; the oil, however, is the activity of the Holy Spirit. Hail, O Peter, gate of sinners, tongue of the disciples, voice of preachers, eye of the Apostles, guardian of heaven, the first-born of the keepers of the keys.” And in another place, “Blessed are you, O Peter, the head and tongue of the body of your brothers, the body which is joined together with the disciples, in which both sons of Zebedi are the eye. They indeed are blessed, who contemplating the throne of the Master, seek a throne for themselves. The true revelation of the Father singles out Peter, who becomes the firm rock.” In another hymn he introduces the Lord Jesus speaking to his first vicar on earth: “Simon, my disciple, I have made you the foundation of the holy Church. I called you “rock” that you might sustain my entire building. You are the overseer of those who build a church for me on earth. If they should wish to build something forbidden, prevent them, for you are the foundation. You are the head of the fountain from which my doctrine is drawn. You are the head of my disciples. Through you all nations shall drink. Yours is that vivifying sweetness that I bestow. I have chosen you to be as a firstborn in my institution and heir to all my treasures. The keys of the kingdom I have given to you, and behold I make you prince over all my treasures.”
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.
22. Therefore, having invoked the Holy Spirit, by Our Supreme Authority, We confer upon St. Ephrem the Syrian, Deacon of Edessa, the title and the honors of Doctor of the Universal Church. We decree that his feastday, which is the 18th of June, is to be celebrated everywhere the birthdays of the other doctors of the Universal Church are celebrated.
23. Therefore, Venerable Brothers, since We rejoice at this increase of honor and glory for our holy Doctor, at the same time We trust that he will be an ever present and eager intercessor for the entire Christian family in these difficult times. May this also be a new testimony to the Eastern Catholics of the special care and interest which the Roman Pontiffs extend to those separated churches. We desire, just as our predecessors did, that their legitimate liturgical customs and canonical prescriptions always remain in integral safety. Would that by the grace of God and the aid of St. Ephrem those obstacles might collapse which separate so large a part of the Christian flock from the mystical rock upon which Christ founded his Church. May that happy day come as soon as possible, on which the words of Evangelical truth will be like “goads and nails firmly fixed” in all minds, words “which are given through authoritative deliberation by one shepherd.”
24. Meantime as a sign of heavenly gifts and a witness of Our paternal charity, We impart to you most lovingly, Venerable Brothers, and to all your clergy and the people entrusted to each one of you, the Apostolic Benediction.
Given at Rome at St. Peter’s, Oct. 5, 1920, the seventh year of Our Pontificate.