This is proved: First, from its title.
This is proved: First, from its title.
(I) From its title. Holy Scripture is called the “canon” and “canonical Scripture.” Therefore it must also be the norm and rule for dogmas in the Church. Ps. 19:4: “Their 
(“line”) has gone out through all the earth.” The Septuagint translation reads 
. Therefore they are reading it as 
, “their sound.” From this Bellarmine (De verbo Dei, bk. 2, c. 2) and Huntlaeus (Contr. 1, c. 9, § 7) conclude that a corruption has crept into the Hebrew text. However, we have explained earlier what response must be given to this argument (§ 331). The rabbinic scholars explain the first part of the psalm—and consequently also this verse—as referring merely to the material heaven: “The cord of their influence,” that is, the works of the planets and stars, “went out through all the world.” But we have an interpreter who is, without any exception, greater: the apostle Paul, who in Rom. 10:18 applies this verse to apostolic doctrine, which today is contained nowhere but in their books. It is called the “rule,” the “norm,” the “canon”—for 
properly signifies: the pointer of a scale, according to which balance is established; the thin cord that workmen imbue with red lead, chalk, or ink to leave a straight line, which guide they later follow in equalizing or planing their lumber; the plumb line, that is, the tool that has lead tied to a string and with which they determine the straightness in height of a structure, a string as much for building as for measurement. Schindlerus notes all of these meanings and more in his Lexicon. Examples of these occur in Job 38:5; Isa. 44:13; Jer. 31:39.
The prophetic statement in Isa. 28:10, somewhat parallel to this, seems to have been taken from this passage of the psalm: “Precept upon precept, 
line upon line, or line after line.” Verse 13: “The Word of the Lord will be to them precept to precept, line to line,” etc. Some people apply this as follows: A builder extends his line until he finishes one row [of bricks], then he moves it and lifts it up to finish another layer. Thus he gradually continues until he finishes the wall. This is like teaching children who gradually grasp things a little at a time. Aben Ezra relates 
to “precepts” and 
to written “doctrine,” as when children learn to read one line after another, lest they be overwhelmed by a multitude. Some take this to mean that precepts and rules are given to stupid, blind people but that they still understand nothing. Thus it is as if it were said to them in a foreign and unintelligible language.
From the entire context it is apparent that this is a discourse about those who hold the Word in contempt, laughing at the prophetic speeches. Therefore the prophet imitates that ridicule of the wicked who often laughed at the repeated warnings of the prophets, saying that they were prattling nothing but “commandment, commandment.” The word “line” is repeated in the same sense. You see, though the prophets were saying that all things had to be examined according to the Word as according to a “line” and “rule,” and were condemning worship that had been dreamed up outside of and beyond the Word, they were being ridiculed by means of this charge by the 
, the wicked despisers and ridiculers, who were teaching that the prophets were bringing forth nothing but their own norm and rule. Therefore when the written Word of God, or Scripture, is called a 
(that is, “rule,” “canon,” or “straightedge,” etc.) by way of a metaphor taken by David and Isaiah from the function of weights on a scale and from architecture, it is thereby established as the norm and rule of all dogmas in the Church.
§ 438. Paul stands in the footsteps of David and Isaiah when he concludes his careful explanation of the article of justification, and therefore his entire Epistle to the Galatians, with something like an ornamentation and seal: “Whoever follows this rule (
), peace and mercy upon them, and upon the Israel of God” (Gal. 6:16). Here it is obvious that the apostle is speaking about his own teaching set forth clearly in this letter written to the Galatians. But now, whatever is the nature of a part among things of the same genus is also the nature of the whole. If the term “canon” is applicable to this Pauline Epistle, then it will also be applicable to the rest of the books of the Old and New Testaments.
Also, because the apostle is using the verb 
, he appears to be drawing us to another aspect of this metaphor. Just as an army is arranged in a certain order to repel hostile incursions, so also when the Church wants to walk in the footsteps of the true faith (Rom. 4:12), to be fortified against the perils of corruption, it needs a definite canon or rule according to which it may walk and within whose limits and boundaries it may keep itself lest it walk into error. That canon or rule, however, is the doctrine that has been divinely revealed through the prophets and apostles and included within their writings. Those who walk according to this norm, who follow this rule in faith and life, “peace and mercy are upon them.” That is, they have a propitious God, a tranquil conscience and a secure heart. They are “the Israel of God,” that is, spiritual Israelites, the people of God, the true Church, etc. Phil. 3:16-17: “Nevertheless to what we have already attained, let us remain in the same rule (
), let us think the same thing. Brethren, join in imitating me and mark those who live thus, just as you have an example (
) in us.” Here, too, the apostle is speaking about that doctrine that he handed down to the Philippians, and he commanded that everything in the Church was to be organized according to that rule of faith and life. Some also refer 2 Cor. 10:13, 15-16 to this point. There the apostle is speaking not so much about the canon of doctrine as about a measure of gifts.
§ 439. From these statements of David, Isaiah, and Paul, it is evident that the name “canon” has been given to Scripture not by human decision but by God Himself and, hence, that God Himself has presented and committed Scripture to us as the only rule of faith and life. To this belong all those statements of Scripture in which the Word of God is called 
, “right” and “the word of uprightness.” For it is and is called “right” not only because it is right, infallible, immovable, and firm in itself, but also because it is the norm of all uprightness in the Church. Ps. 19:[8]: “The precepts of the Lord are 
(“right”), rejoicing the heart.” Ps. 45:[6]: “The scepter of your kingdom is a 
(“scepter of righteousness” or “right scepter”).” Eccl. 12:[10]: “The Preacher sought to find words of 
(“of desire,” “pleasing, delightful”) and a right Scripture (
, “a Scripture of uprightness,” as Benedictus Arias Montanus puts it).”
Tell me, what else is Holy Scripture than the speech of God and Christ written down in letters through the prophets, evangelists, and apostles? The Spirit of Christ spoke through the prophets (1 Pet. 1:11). From Christ the apostles received the Holy Spirit, at whose impulse they taught and wrote. But if Christ’s speech is a right scepter, right speech, a scepter of uprightness, then Holy Scripture must certainly also be the right norm of all righteousness in the Church and the rule of all uprightness. The Philosopher, in De anim. 1, last chapter, says, “By what is straight we know both it and what is crooked, for the rule [
] is the judge of both.” He also uses the term “canon” for rules and precepts in Ethic., bk. 3, c. 4. In bk. 2, c. 3, 
to him means “to arrange something according to a rule.” Therefore when the term “canon” is attributed to Scripture, it is thereby established as the rule for a spiritual building. The Papists use this word quite often, for they call the decrees of popes and councils “canons.” Also, they have the Canon of the Mass, the canon for the deceased saints, canonical brothers of certain monastic rules [canonicos regulares], canonical hours, canons of the apostles, etc. In all these examples the word “canon” has the meaning of a rule or norm. They should admit, therefore, that the same word is attributed to Holy Scripture in the same sense.