Therefore the Divine Office must be ruled by our Fathers’ authority, not by private judgment
This proposition is proved from what has gone before and furthermore is handed down explicitly in the Rule of Canons, where we find these words: “And do not sing anything but what is noted to be sung; and what is not so noted is not to be sung.”
Here the venerable Hugh of St. Victor says in his Explanation of the Rule:
It is not right that the church singing should be varied according to the ideas of different persons. It should be steadily maintained according to the written and traditional use of those that have gone before us. In the same way all other customs of the convent ought to be regulated by authority and discretion. And if aught is to be changed or newly established, this should not be hastily or lightly decided upon, nor yet merely on the opinion of two or three. But the matter should be arranged as the chief part of the chapter shall judge best, when all have been gathered together to consider it. We must know that ecclesiastical authority is always to be followed before private reasoning. For authority is ever the safeguard of humility and obedience, whereas reason not unfrequently leads to presumption. This principle is always to be regarded in a religious order if it is to shine by maturity and gravity. St Paul says of himself: “Did I use lightness . . . that there should be with me, It is and it is not?” (2 Cor. 1:17) For it is becoming, and especially in keeping with the religious state, to refrain from easily or lightly introducing change.
And in the eleventh distinction Pope Julius says: “Do not wander, my brethren, do not be led astray by new and alien doctrines; keep the institutes of the apostles and apostolic men and the canons”; and “do not, against the Apostle’s desire, be carried about with every wind of doctrine (Eph. 4:14),” in the twelfth distinction, chapter De his.
Lord Norbert may be a religious and holy man, boasting many divers virtues, well-versed in the holy scriptures, a paragon of preachers. Yet still we ought not put as much faith in him as in our holy fathers whose names are written in the book of life, who performed famous miracles, who support and enrich the Church daily with their examples, and whose zeal causes the canonical order to flourish and bear fruit today. Though people regard Norbert as a good man, it is not known whether he be one of the elect before God. Further, we declare that the novel form of the canonical office he promoted, with its antiphons and psalms alternating in a cycle of three seasons, runs afoul of the sacred canons and of St. Augustine himself. For if we are called canons and profess the canonical life, then we must embrace the canons given to us by our mother the Roman Church, especially in what pertains to the Divine Office, for we have received our very name from them. Nay, he who invents false or new opinions against her and persists in following them is judged a heretic. In order to show us with what great presumption we stray in altering the Office, we call our holy Fathers to witness. They are our defense and yours against this unsanctioned religious innovation.
Then after citing and quoting the chapters Si instituta and Quis nesciat in the eleventh distinction, both referenced earlier, the chapter In die in De consecratione distinction five, [Inferius sollemnizando,] the chapter Observetur, the chapter Illa autem in the twelfth distinction, the chapter In his rebus in the eleventh distinction, and the chapter Illud te breviter in the twelfth distinction, he concludes: “Behold with what authorities and customs we dispense your religious order, nay, the entire Church, from those vain institutions.” And he ends: “And so we desire, beseech, and counsel you to depart from these contentions which kindle schism and give rise to scandal among God’s people.”
Let us return to the letter of the Rule: ‘Do not.’ Speech in the imperative mood falls under precept, as in the Clementinae 5, tit. 11 De verborum significatione, cap. Exivi, Ut autem haec, where it speaks of the office of the Friars Minor. There the Lord Pope says that these words of the Rule of St. Francis, “Let the clerics perform the Divine office according to the order of the holy Roman Church” are a matter of precept which “the friars are obliged to observe.” It follows that “those who violate this precept are guilty of mortal sin.” Thus, “A rule is an order, and what is ordered must be done; if it is not done, there are grounds for punishment. One who offers advice does so at his own discretion; one who orders obliges obedience,” according to St. Gregory, as found in the thirteenth distinction, question 1, Quod praecipitur.
The Rule continues: ‘Sing.’ This word is generally understood to refer to all the psalmody, reading, and chants said in the divine offices, for all serve the same purpose, and in common parlance are called “song.”
It continues, ‘Except what is noted in approved writings.’ For the holy Doctor has nothing to say about spurious writings. Going on, “But what is not so noted.” This phrase might seem superfluous, since he just forbade “what is not noted,” and therefore cannot be read, to be sung. But he was referring above to the sung texts themselves; now he prescribes the manner of singing, saying that what must be sung should be sung in no other way or manner than as they are noted. Deuteronomy, chapter 10 at the end: “What I command thee, that only do thou to the Lord: neither add any thing, nor diminish.”
Thus the Rule prescribes three things: that what is noted should be observed, that what is not noted should be rejected, and that what is noted should be sung just as it is noted. Thus supposes, as is true, that everything is in fact written down. The Rule does not say “what seculars do by custom,” or “what jurists recommend,” or “what the pope commands,” but “what is written,” what is prescribed, what is instituted should be read, sung, and observed in the office. But what is not noted or done by universal custom must be rejected, as above in the second Proposition.
But if a person should object to the contrary that one should leave aside the canons, bishops’ statutes, and general customs and follow the metropolitan church’s manner of singing, since as much is written in the twelfth distinction, chapter De his; in De consecratione distinction 1, Altaria; and in the second distinction, chapter Institutio, we would respond that these chapters pertain to matters which have not been determined by canons, statues, or general custom; such things are blown hither and thither by the wind of doctrine, as written in the cited chapter De his. But in certain things, we must follow what is certain and determined.
 St. Augustine, Regula ad servos Dei, c.3 — ML 32:1379 (Augustine of Hippo, Epistola 211 (CSEL 57: 361).
 Hugh of St. Victor, Expositio in regulam sancti Augustini 3 — PL 176:892. The English translation of the work, which is considered Victorine but not by Hugh, is Explanation of the Rule of Saint Augustine by Hugh of St. Victor, trans. Dom Aloysius Smith, C.R.L. (London, 1911), 30.
 CJC, Decr. I, 11.3 — Frdbg. I, 23.
 CJC, Decr. I, 12.13 — Frdbg. I, 30.
 See Frédéric de Reiffenberg, “Chartes inédites communiqués par M. le baron de Reiffenberg,” in Compte rendu des séances de la Commission Royale d’histoire, vol. 9 (1844), 102–103.
 For a modern edition, see Charles Dereine, S.J., “Saint-Ruf et ses coutumes aux XIe et XIIe siècles,” in Revue Bénédictine 59 (1949):1-4, 167–174.
 The ancient text circulating under the name Regula secunda or Ordo monasterii (OM) and attributed to Augustine divided the year into three periods, each allotted different numbers of nocturnal psalms and lessons. Cf. an analogous arrangement in a contemporary customary of the Augustinian abbot Richard of Springiersbach, Charles Dereine, “Les Coutumiers de Saint-Quentin de Beauvais et de Springiersbach,” in Revue Bénedictine 43 (1948):439-440. Elsewhere, Dereine argues that the “contentions” Walter mentions toward the end of his letter resulted from Norbert’s attempt to apply the OM in early Norbertine houses, “Le premier Ordo de Prémontré,” in Revue Benedictine 58 (1948): 84–92.
 Gualterius (Walter), bishop of Montpellier (r. 1104–1128). See P. Gams, O.S.B., Series episcoporum (Regensburg, 1873), 579 — Gallia christiana, vol. 6, pg 745–48 —- Hurter, Nomenclator, vol. 2, pg. 61, Innsbruck, 1906; Trichemius, De scriptoribus ecclesiasticis, no. 402 — The Premonstratensian Kloster Roggenburg, in Chamousey, France. Cf. Gallia Christiana, vol. 13, pg. 1419ff. For an account of the early controversy over the Premonstratensian office, which was defended by Jacques de Vitry, see Archdale King, Liturgies of the Religious Orders (1955), pp. 167.
 Ivo, Decr. IV, 67 — PL 161:282.
 CJC, Decr. I, 11.11 — Frdbg. I, 26.
 CJC, Decr. III, 5.15— Frdbg. I, 1416.
 This Latin text is not found as a canon title, Mohlburg’s apparatus ignores it, and Walter’s letter in fact passes directly from In die to Observetur.
 CJC, Decr. I, 12.11 — Frdbg. I, 29.
 CJC, Decr. I, 11.7 — Frdbg. I, 25.
 CJC, Decr. I, 12.4 — Frdbg. I, 28.
 CJC, Clementine V, 44.1— Frdbrg. II, 1194f.
 St. Francis, Rule 3.
 See Bernard, Book on Precept and Dispensation, ??. [ch 1.2]
 CJC, Decr. II, 14.1.3 — Frdbrg. I, 733.
 Deuteronomy 12:32.
 CJC, Decr. I, 12.13 — Frdbg. I, 30f.
 CJC, Decr. III, 1.31 — Frdbg. I, 1302.
 CJC, Decr. III, 2.31 — Frdbg. I, 1324.
 Eph 4:14.