Thomas Aquinas, on 1Cor 11:19

“For there must be also heresies: that they also, who are approved, may be made manifest among you.”

“Secondly, he presents the credulity of his hearers when he says: And I partly believe it, i.e., as to some of you who were prone to contention, according to what was said above (1:11): "There is quarreling among you. What I mean is that each of you says, 'I belong to Paul,' or 'I belong to Apollos' or 'I belong to Cephas.'" But others were not contentious, who said: "I belong to Christ." Hence it says in S. of S. (2:2): "As a lily among brambles, so is my love among maidens," i.e., good among the evil. Thirdly, he assigns the reason for their credulity, saying: For there must be not only factions among you but also heresies. Two things must be considered here: first, what heresy is; secondly, how it is necessary that there be heresies. In regard to the first it should be known that, as Jerome comments on the epistle to the Galatians, the Greek word, "heresy," means "election" or "choice," namely, because each one selects for himself that discipline which he considers to be better. From this two things can be taken: first, that it is of the very nature of heresy that a person follow his own private discipline, as though by his own choice, but not the public discipline handed down by God. Secondly, that he obstinately cling to this discipline. For choice implies firm adherence; and therefore the heretic is one who scorns the discipline of the faith handed down by God and obstinately follows his own error. Now something pertains to the discipline of the faith in two ways: in one way directly, as the articles of faith, which are proposed to be believed of themselves. Hence an error in regard to them makes one a heretic, if obstinacy is present. But a person cannot be excused from such an error on account of some simplicity especially in regard to those about which the Church made a solemn proclamation and which are generally spoken about by the faithful, such as the mystery of the Trinity, the birth of Christ, and so on. But other things pertain to the discipline of the faith indirectly, namely, inasmuch as they are not proposed as something to be believed of themselves, but from their denial something contrary to the faith follows; for example, if it is denied that Isaac was the son of Abraham, something contrary to the faith follows, namely, that Sacred Scripture contains something false. From such things one is not judged heretical, unless he continues in his opinion so obstinately, that he would not depart from his error, even though he sees what follows from his position. Therefore, the obstinacy with which someone spurns the judgment of the Church in matters pertaining to the faith directly or indirectly makes a man a heretic. Such obstinacy proceeds from pride, whereby a person prefers his own feelings to the entire Church. Hence the Apostle says in 1 Tim (6:3): "If anyone teaches otherwise and does not agree with the sound words of our Lord Jesus Christ and the teaching which accords with godliness, he is puffed up with conceit, he knows nothing; he has a morbid craving for controversy and for disputes about words." Secondly, it must be considered how it is suitable that heresies exist. For if it is suitable for heretics to be, it seems that they are commendable and should not be stamped out. But it should be noted that there are two ways in which something is described as suitable to be. In one way from the intention of the one who does this; for example, if we should say that judgments ought to be, because judges make judgments intending to establish justice and peace in human affairs. In another way from the intention of God Who ordains evil things to good, Who directs the persecutions of tyrants to the glory of the martyrs. Hence Augustine says in Enchiridion that God is so good that He would not permit evil in any way, unless He were powerful enough that from each evil He can draw some good. And according to this it says in Matt (18:7): "Woe to the world for temptations to sin. For it is necessary that temptations come, but woe to that man from whom temptations come." And according to this the Apostle says the heresies must be, inasmuch as God has ordained the malice of heretics to the good of the faithful. He says this, first, for the clearer declaration of truth. Hence Augustine says in The City of God: "A question raised by an adversary is an occasion for learning; indeed, many things pertaining to the Catholic faith, when they are devised by the clever energy of heretics, in order that they may be defended against them, are considered more carefully and understood more clearly and preached with more emphasis." Hence it says in Pr (27:17): "Iron sharpens iron; and one man sharpens another." Secondly, to reveal the weakness of faith in those who believe rightly. And this is what the Apostle says: in order that those who are genuine, i.e., approved by God, may be recognized among you: "Like gold in the furnace he tried them" (Wis 3:6).”

Imported from an open dataset — not yet checked against the printed edition.