Complete Works of Lactantius Vol. II

19. In the Pontifical Book Liber Pontificalis, a collection of biographies of the Popes, two decrees are ascribed to the same Pope: the first, which mandates, "That no believer should hold a fast on the Lord's Day Sunday or on Thursday: because pagans celebrate these days as a holy fast." To which decree in the same Pontifical Book is immediately appended, "And the Manichæans were found in the city of Rome by the same [pope]."

20. However, it is clear in two ways that this decree is falsely ascribed to Melchiades: first, because even before the times of this Pope, fasting was forbidden to the faithful on the Lord's Day; second, because the reason for the prohibition was not that pagans or gentiles were holding it as a holy fast, but because Christians judged that fasting did not at all befit the day on which Christ gladdened the Church with His resurrection. Moreover, the need to guard against this, which they had learned through custom and tradition—which teaches that the Lord's Day is to be spent festively—they began to observe with greater religion when the Manichæans, not the pagans, began to hold this day as a holy fast. Lest we appear to say this without cause, both must be proven briefly.

21. Before the age of Melchiades, Tertullian wrote in his book On the Crown, ch. 3: "We consider it a sin to fast on the Lord's Day." It is also read at the end of the fifth book of the Apostolic Constitutions: "For he who fasts on the Lord's Day will be guilty of sin, since it is the day of the resurrection." No other reason is given here. But subsequently Augustine, in Epistle 36 to Casulanus, ch. 12, n. 27, saying: "To fast on the Lord's Day is a great scandal," added this new reason: "especially after the detestable heresy of the Manichæans became known, which is most openly contrary to the apostolic faith and the divine Scriptures, and which constituted this day as a legitimate one for its auditors to fast upon. By which fact it happened that the fast of the Lord's Day was held in greater horror." And in n. 29, he teaches that one must especially guard against celebrating a fast on the Lord's Day, "after heretics, especially the most impious Manichæans, began to perform the fasts of the Lord's Day not because of any necessity that arose, but to dogmatize it as if it were a holy solemnity." Pope Leo also attests to this regarding the same heretics, in Epistle 17 to Turibius, ch. 4: "Just as they were detected and convicted in our examination, they demand that the Lord's Day, which the resurrection of our Savior has consecrated for us, be spent in the sorrow of a fast." Therefore, in the Pontifical Book it would not seem absurd if it had been said: "The Manichæans were found in the city of Rome by Melchiades. Then that Pope decreed that no believer should hold a fast on the Lord's Day: because those heretics celebrate this day as a holy fast." Mercator, however, by no means correcting the Pontifical Book, but imitating it according to custom, introduces Melchiades decreeing thus: "No one ought to celebrate the fast of the Lord's Day or Thursday: so that between the fast of Christians and that of gentiles, of true believers and of infidels and heretics, there may be a true and not a false distinction."

22. Around the time of the Nicene Council, a certain Eustathius was doing and teaching many things akin to the tenets of the Manichæans, against whom the Synod of Gangra, gathered in canon 18, according to the interpretation of Dionysius Exiguus, decreed: "If anyone, because of the continence that is supposed, or out of stubbornness, fasts on the Lord's Day, let him be anathema." Where this council, just like the Council of Saragossa against the Priscillianists—who were also accustomed to be called Manichæans—celebrated in the year 381, while canon 2 prohibits "anyone from fasting on the Lord's Day because of time or persuasion or superstition," seems in a way to permit fasting even on the Lord's Day, provided the cause of superstition is absent. And indeed, Jerome writes in Epistle 28 to Lucinius: "I wish we could fast at all times: for we read in the Acts of the Apostles (as Augustine also observed in Epistle 36, n. 28) that the apostle Paul and the believers with him did so on the days of Pentecost and the Lord's Day." Yet, lest he appear to disapprove of the custom and law of the Church, he immediately tempers his statement, adding: "I do not say this because I think one should fast on Lord's Days."

23. This law, as Epiphanius testifies (Epiph., Exposition of the Faith, n. 22), was observed so religiously that even those who imposed perpetual fasts upon themselves with the greatest zeal for piety excepted only the Lord's Days and Pentecost: "For, he says, the Church has sanctioned all Lord's Days as festive and joyful, and celebrates no fasts. For it is absurd to fast on the Lord's Day... Nor is the Church accustomed to fast on the Sundays of Lent itself." Conversely, the same saint, in Heresies 75, n. 3, rightly reproves the Aerians because, through a foolish display of liberty, "they prefer to fast on the Lord's Day, but eat on the fourth and sixth day of the week." No less vain are the heterodox of our age, who place Christian liberty in the despising of the laws of abstinence and fasting, which the Church, taught by Christ and His Apostles, has wisely instituted. It is the Church that, while it has stirred the faithful to fast either by exhortations or by precepts, has always excepted the Lord's Day, not to separate them from the gentiles, but to teach that the day of the Lord's resurrection must always be celebrated festively. It is therefore falsely posited that Melchiades decreed that no one should hold a fast on the Lord's Day. Nor is it any less falsely narrated in the Pontifical Book that he decreed the same concerning Thursday.

24. There was never such a religion among Christians regarding Thursday that they were prohibited from fasting on this day. The custom prevailed only that, while some fasted on the fourth and sixth days, and others on the sixth and the Sabbath, most judged that they should abstain from fasting on Thursday, which is near to those days consecrated by fasting. Hence the Apostolic Constitutions (book V, ch. 24), exhorting us against the custom of hypocrites who always affect singularities, command: "Let not our fasts be common with the hypocrites; for they fast on the second and the fifth day of the week." And Augustine, in Epistle 36, ...