Ambrosiaster : Paul means that knowledge is a great thing and very useful to the person who has it, as long as it is tempered by love. — COMMENTARY ON PAUL'S EPISTLES Augustine of Hippo : Paul means that knowledge only does good in company with love. Otherwise it merely puffs a man into pride. — City of God 9.20 Clement of Alexandria : "If any man thinketh that he knoweth anything, he knoweth nothing yet as he ought to know." For truth is never mere opinion. But the "supposition of knowledge inflates," and fills with pride; "but charity edifieth," which deals not in supposition, but in truth. Whence it is said, "If any man loves, he is known." — The Stromata Book 1 Clement of Alexandria : But the knowledge of those who think themselves wise, whether the barbarian sects or the philosophers among the Greeks, according to the apostle, "puffeth up." But that knowledge, which is the scientific demonstration of what is delivered according to the true philosophy, is rounded on faith. — The Stromata Book 2 Clement of Alexandria : "We know that we all have knowledge"-common knowledge in common things, and the knowledge that there is one God. For he was writing to believers; whence he adds, "But knowledge (gnosis) is not in all," being communicated to few. And there are those who say that the knowledge about things sacrificed to idols is not promulgated among all, "lest our liberty prove a stumbling-block to the weak. For by thy knowledge he that is weak is destroyed." — The Stromata Book 4 Irenaeus : It is therefore better and more profitable to belong to the simple and unlettered class, and by means of love to attain to nearness to God, than, by imagining ourselves learned and skilful, to be found [among those who are] blasphemous against their own God, inasmuch as they conjure up another God as the Father. And for this reason Paul exclaimed, "Knowledge puffeth up, but love edifieth:" not that he meant to inveigh against a true knowledge of God, for in that case he would have accused himself; but, because he knew that some, puffed up by the pretence of knowledge, fall away from the love of God, and imagine that they themselves are perfect, for this reason that they set forth an imperfect Creator, with the view of putting an end to the pride which they feel on account of knowledge of this kind, he says, "Knowledge puffeth up, but love edifieth." Now there can be no greater conceit than this, that any one should imagine he is better and more perfect than He who made and fashioned him, and imparted to him the breath of life, and commanded this very thing into existence. It is therefore better, as I have said, that one should have no knowledge whatever of any one reason why a single thing in creation has been made, but should believe in God, and continue in His love, than that, puffed up through knowledge of this kind, he should fall away from that love which is the life of man; and that he should search after no other knowledge except [the knowledge of] Jesus Christ the Son of God, who was crucified for us, than that by subtle questions and hair-splitting expressions he should fall into impiety. — Against Heresies Book II John Chrysostom : "Now concerning things sacrificed to idols, we know that we all have knowledge." Leaving alone the weak, which he always doth, he discourses with the strong first. And this is what he did also in the Epistle to the Romans, saying, "But thou, why dost thou judge thy brother?" for this is the sort of person that is able to receive rebuke also with readiness. Exactly the same then he doth here also. And first he makes void their conceit by declaring that this very thing which they considered as peculiar to themselves, the having perfect knowledge, was common to all. Thus, "we know," saith he, "that we all have knowledge." For if allowing them to have high thoughts, he had first pointed out how hurtful the thing was to others, he would not have done them so much good as harm. For the ambitious soul when it plumes itself upon any thing, even though the same do harm to others, yet strongly adheres to it because of the tyranny of vain-glory. Wherefore Paul first examines the matter itself by itself: just as he had done before in the case of the wisdom from without, demolishing it with a high hand. But in that case he did it as we might have expected: for the whole thing was altogether blameworthy and his task was very easy. Wherefore he signifies it to be not only useless, but even contrary to the Gospel. But in the present case it was not possible to do this. For what was done was of knowledge, and perfect knowledge. Nor was it safe to overthrow it, and yet in no other way was it possible to cast out the conceit which had resulted from it. What then doeth he? First, by signifying that it was common, he curbs that swelling pride of theirs. For they who possess something great and excellent are more elated, when they alone have it; but if it be made out that they possess it in common with others, they no longer have so much of this feeling. First then he makes it common property, because they considered it to belong to themselves alone. Next, having made it common, he does not make himself singly a sharer in it with them; for in this way too he would have rather set them up; for as to be the only possessor elates, so to have one partner or two perhaps among leading persons has this effect just as much. For this reason he does not mention himself but all: he said not, "I too have knowledge," but, "we know that we all have knowledge." This then is one way, and the first, by which he cast down their pride; the next hath greater force. What then is this? In that he shews that not even this thing itself was in all points complete, but imperfect, and extremely so. And not only imperfect, but also injurious, unless there were another thing joined together with it. For having said that "we have knowledge," he added, "Knowledge puffeth up, but love edifieth:" so that when it is without love, it lifts men up to absolute arrogance. "And yet not even love," you will say, "without knowledge hath any advantage." Well: this he did not say; but omitting it as a thing allowed by all, he signifies that knowledge stands in extreme need of love. For he who loves, inasmuch as he fulfils the commandment which is most absolute of all, even though he have some defects, will quickly be blest with knowledge because of his love; as Cornelius and many others. But he that hath knowledge but hath not love, not only shall gain nothing more, but shall also be cast out of that which he hath, in many cases falling into arrogance. It seems then that knowledge is not productive of love, but on the contrary debars from it him that is not on his guard, puffing him up and elating him. For arrogance is wont to cause divisions: but love both draws together and leads to knowledge. And to make this plain he saith, "But if any man loveth God, the same is known of Him." So that "I forbid not this," saith he, "namely, your having perfect knowledge; but your having it with love, that I enjoin; else is it no gain, but rather loss." Do you see how he already sounds the first note of his discourse concerning love? For since all these evils were springing from the following root, i.e., not from perfect knowledge, but from their not greatly loving nor sparing their neighbors; whence ensued both their variance and their self-satisfaction, and all the rest which he had charged them with; both before this and after he is continually providing for love; so correcting the fountain of all good things. "Now why," saith he, "are ye puffed up about knowledge? For if ye have not love, ye shall even be injured thereby. For what is worse than boasting? But if the other be added, the first also will be in safety. For although you may know something more than your neighbor, if you love him you will not set yourself up but lead him also to the same." Wherefore also having said, "Knowledge puffeth up," he added, "but love edifieth." He did not say, "Behaveth itself modestly," but what is much more, and more gainful. For their knowledge was not only puffing them up but also distracting them. On this account he opposes the one to the other. — Homily on 1 Corinthians 20