As welcome to me as it always is to receive the letters of your beloved reverence, so is it also fitting that our own writings be directed to you in turn; especially since we do this not merely for the sake of a common friendship, but far more for the state of the universal Church. Therefore, through our brothers Lucentius the bishop and Basil the presbyter, whom we had signified that we were about to send to Constantinople, I now repay the discourse that is owed, admonishing you to deign to associate the zeal of your diligence with them in all things, so that whatever remnants of scandals still survive may be shrewdly removed. For although the light of the catholic faith now shines everywhere, and, what is most powerful of all, the hearts of Christian princes are subject to the divine authorities:
there are nevertheless certain matters which that Ephesine tumult so confounded that they must be handled with great restraint, lest the evils of dissension which have arisen from it should persist. What therefore has been enjoined and committed to our legates, you will learn from their own explanation, bestowing upon me and upon them such affection that whatever has been entrusted to them may—your beloved zeal and solicitude being joined to it, and the Lord assisting—arrive at that effect which we desire. Given on the fifth day before the Ides of June, in the consulship of the most illustrious man Adelfius. To turn aside the stain of error, with which the Nestorian impiety or the Eutychian madness has undermined not a few, the presbyters Basil and John, our sons, took praiseworthy care for their own esteem;
that amid conflicting dogmas of falsehood they might rejoice in the true peace of the catholic faith. For, having undertaken the labor of a distant pilgrimage, they laid open the mind of their heart before the apostolic See, condemning both heresies, of which we have made mention above, and receiving concerning the incarnation of our Lord Jesus Christ nothing other than what, the Holy Spirit teaching, we both have learned and do teach. Through these men therefore, most dear brother, returning to their own homes with our testimony, we have directed our writings to your beloved reverence, confidently exhorting that those who are adorned with the grace of apostolic communion may rejoice to be aided in all things also by your favor. Given on the thirteenth day before the Kalends of July, in the consulship of the most illustrious man Adelfius.
1. A question long before agitated concerning the Pasch of the year 444 made Leo anxious to write in good time concerning the day of the Pasch of the year 455, in which he was not unaware that the cycles of the Romans and of the Alexandrians disagreed. Hence, already from the year 451, in which the following letter was written, he bent his zeal to have this day fixed by unanimous consent. We possess besides nine letters of the same pontiff, drawn up in subsequent years upon the same matter, apart from several others which are wanting; and one of Proterius of Alexandria to the same pontiff, which we shall give in their proper places. 2. From the Paschal table of Theophilus of Alexandria for a hundred years, which consisted of five nineteen-year cycles and five years, the Pasch of the year
455 was assigned to the eighth day before the Kalends of May. But from the Latin cycle of eighty-four years it was ascribed to the fifteenth day before the Kalends of the same month, and therefore a discrepancy of eight days intervened. Now this discrepancy arose from the lunar 'leaps' (saltus lunae), which the Latins admitted more frequently, but the Alexandrians more rarely. For whereas the Alexandrians, from their nineteen-year cycle, set the lunar leaps—by which the age of the moon is increased by one day through the leap—in every nineteenth year, the Latins on the other hand, from their cycle of eighty-four years, up until the emendation of Prosper, admitted those leaps every twelfth year, but after the emendation of Prosper in each fourteenth year:
the age of the moon, from which the paschal day is determined, among the Romans, on account of leaps more frequent than among the Alexandrians, in the year 455 grew by three days, so much so that the moon which for the Alexandrians in that year on the fifteenth day before the Kalends of May, a Sunday, was the fourteenth, was for the Romans the seventeenth. But since the Pasch cannot be celebrated on the fourteenth of the moon, lest we coincide with the Hebrews, hence the Alexandrians were compelled to defer the Pasch to the following Sunday, the eighth day before the Kalends of May. Among the Latins, however, since on that day, the fifteenth before the Kalends of May, it was the seventeenth of the moon, nothing prevented them from celebrating the Pasch on that day; but several things stood in the way of their transferring that feast, with the Alexandrians, to the eighth day before the Kalends of May.
3. First, on that day the age of the moon for them was the twenty-fourth; and if they had celebrated the Pasch then, they would have exceeded by two days the extreme limit of the moon's age, which among them was the twenty-second of the moon. Then, moreover, they would have exceeded by three days the ultimate limit of the paschal Sundays, which for them was the eleventh day before the Kalends of May. As to these limits of the paschal Sundays, the matter was reconciled in the year 444, for the reason that Leo was persuaded that it sufficed if the day of the Passion in no way exceeded that limit, the eleventh before the Kalends of May; whereby it came about that, this limit being observed, upon which the day of the Passion then fell, the Pasch was that year celebrated by the Latins also, following the calculation of the Alexandrians, two days later, that is, on the ninth day before the Kalends of May.
But this method of reconciliation availed nothing in the question concerning the Pasch of the year 455, in which, the paschal day being prolonged not only by two but by three days, it overpassed that ultimate limit of the Passion itself. The Latins thought, finally, that according to the Alexandrians' reckoning the Pasch would be celebrated in the second month, whereas by law it ought to be celebrated in the first month; for they seem to have reckoned the first month from the day of the equinox, the twenty-first of March, to the twenty-first of April. 4. The Alexandrians brought forward many things against these objections of the Latins. But since they always disputed on the hypothesis that on the eighth day before the Kalends of May
was the fourteenth of the moon—and never, at least from the surviving records, did they convict the Latins of error while these assigned a different age of the moon to that day, nor did they touch at all upon the differing lunar leaps, from which the differing age of the moon proceeded (in which, had they persuaded the Latins to be in error, they would doubtless have obtained their assent; for the Latins were not forbidden by their own rules to celebrate the Pasch on the fourteenth of the moon only, but even on the fifteenth)—it is no wonder if St. Leo showed himself not convinced by the Alexandrians' reasonings, and only out of zeal for unity and peace appointed the Pasch according to their opinion. Let it suffice to have premised these few things, so that the matters which are indicated in the letters to be presented concerning this controversy may be understood.
Some other matters, where need shall require, will be subjoined in the annotations. But we have prefixed this admonition to the following letter, because it is the first that gives an indication of this paschal controversy. CHAPTER I. — Although I do not doubt that the whole origin of the scandals which have been stirred up in the Eastern Churches concerning the incarnation of our Lord Jesus Christ has been fully ascertained by your fraternity, nevertheless, lest anything perchance might have been able to escape your solicitude, I have directed to you, to be more carefully perused and understood, our letter—most full upon this matter—which we sent to Flavian of holy memory, and which the universal Church embraces:
so that, understanding with what fullness the impiety of this whole error has, by God's help, been destroyed, you yourself also may, out of your love toward God, take up the same spirit, and may know that those are utterly to be detested who, according to the impiety and madness of Eutyches, dared to say that in our Lord, the only-begotten Son of God, taking upon Himself the restoration of human salvation, there are not two natures—that is, of perfect Divinity and of perfect humanity; and they think that they can deceive our diligence when they say that they believe one nature of the Word to have been made flesh; whereas indeed the Word of God, in the Divinity of the Father, and His own, and of the Holy Spirit, is of one nature;
but, the truth of our flesh having been assumed, our nature also has been united to that unchangeable substance: for it could not even be called an incarnation, unless the flesh were assumed by the Word. And this assumption is so great and such a union, that from the animated flesh no division of the Divinity is to be believed, not only in the childbearing of the blessed Virgin, but even in the conception: since in the unity of person the Divinity and the humanity came together both in the conception of the Virgin and in the childbearing. CHAPTER II. — To be abominated therefore is the impiety in Eutyches, which of old was condemned and destroyed by the Fathers in preceding heretics; which ought to have profited this most foolish man:
so that what he could not apprehend by understanding, he might at least guard against by the preceding example, lest, by denying the truth of human flesh in Christ our Lord, he should empty the singular sacrament of our salvation. For if a true and perfect nature of humanity is not in Him, there is no assumption of ours; and the whole of what we believe, what we teach, is, according to his impiety, vanity and a lie. But since neither does the truth lie, nor is the Divinity passible, there remains in God the Word each substance in one person; and thus the Church confesses her Savior, so that she affirms Him both impassible in the Divinity and passible in the flesh, as the Apostle says: Though He was crucified through weakness, yet He liveth by the power of God (2 Cor. 13:4). CHAPTER
III. — But that your beloved reverence may in all things be more fully instructed as to what our holy Fathers thought concerning the sacrament of the incarnation of the Lord, and what they preached to the Churches, so that you might evidently recognize it, I have transmitted to your love certain writings, which our men also, at Constantinople, adduced together with my letter. And you shall know that the whole Church of Constantinople, with all the monasteries and many bishops, gave its consent, and by their subscriptions anathematized Nestorius and Eutyches together with their dogmas.
You shall also know that recently I received a letter of the bishop of Constantinople, which reports that the bishop of Antioch, having sent circular letters throughout his provinces, brought all the bishops likewise to give consent to my letter, and to condemn Nestorius and Eutyches with equal subscription. CHAPTER IV. — This too we believe must be enjoined to your care, that, since the method of the paschal feast does not lie hidden from your experience, concerning that which we have found in the annotation of Theophilus, and which disquiets us, you would more diligently inquire there, and deal it over with those who are able to have skill in this computation and rule: in what manner the day of the Lord's resurrection in the fourth ensuing year is to be held.
For whereas the coming Pasch, God being propitious, is to be held on the tenth day before the Kalends of April, and the next on the day before the Ides of April, the third on the day before the Nones of April, for the fourth Theophilus of holy memory appointed it to be observed on the Kalends of May: which we find utterly foreign to ecclesiastical rule; but in our paschal cycles, as you deign well to know, it is written that the Pasch of that same year is to be celebrated on the fifteenth day before the Kalends of May. And therefore, that all ambiguity may be removed from us all, let your solicitude more diligently deal this matter over with any who are skilled, that in the future we may guard against an error of this kind. Given on the eighth day before the Kalends of July, in the consulship of the most illustrious man Adelfius.