Matthew 13:25

The Devil is called a man that is an enemy because he has ceased to be God; and in the ninth Psalm it is written of him, Up, Lord, and let not man have the upper hand. (ver. 19) Wherefore let not him sleep that is set over the Church, lest through his carelessness the enemy should sow therein tares, that is, the dogmas of the heretics.

(Quaest. in Matt. q. 11.) He says, While men slept, for while the heads of the Church were abiding in supineness, and after the Apostles had received the sleep of death, then came the Devil and sowed upon the rest those whom the Lord in His interpretation calls evil children. But we do well to enquire whether by such are meant heretics, or Catholics who lead evil lives. That He says, that they were sown among the wheat, seems to point out that they were all of one communion. But forasmuch as He interprets the field to mean not the Church, but the world, we may well understand it of the heretics, who in this world are mingled with the good; for they who live amiss in the same faith may better be taken of the chaff than of the tares, for the chaff has a stem and a root in common with the grain. While schismatics again may more fitly be likened to ears that have rotted, or to straws that are broken, crushed down, and cast forth of the field. Indeed it is not necessary that every heretic or schismatic should be corporally severed from the Church; for the Church bears many who do not so publicly defend their false opinions as to attract the attention of the multitude, which when they do, then are they expelled. When then the Devil had sowed upon the true Church divers evil errors and false opinions; that is to say, where Christ's name had gone before, there he scattered errors, himself was the rather hidden and unknown; for He says, And went his way. Though indeed in this parable, as we learn from His own interpretation, the Lord may be understood to have signified under the name of tares all stumbling-blocks and such as work iniquity.

What is the difference between this, and the parable before it? There He speaks of them that have not at all holden with Him, but have started aside, and have thrown away the seed; but here He means the societies of the heretics. For in order that not even this might disturb His disciples, He foretells it also, after having taught them why He speaks in parables. The former parable then means their not receiving Him; this, their receiving corrupters. For indeed this also is a part of the devil's craft, by the side of the truth always to bring in error, painting thereon many resemblances, so as easily to cheat the deceivable. Therefore He calls it not any other seed, but tares; which in appearance are somewhat like wheat. Then He mentions also the manner of his device. For "while men slept," saith He. It is no small danger, which He hereby suspends over our rulers, to whom especially is entrusted the keeping of the field; and not the rulers only, but the subjects too. And He signifies also that the error comes after the truth, which the actual event testifies. For so after the prophets, were the false prophets; and after the apostles, the false apostles; and after Christ, Antichrist. For unless the devil see what to imitate, or against whom to plot, he neither attempts, nor knows how. Now then also, having seen that "one brought forth a hundred, another sixty, another thirty," he proceeds after that another way. That is, not having been able to carry away what had taken root, nor to choke, nor to scorch it up, he conspires against it by another craft, privily casting in his own inventions. And what difference is there, one may say, between them that sleep, and them that resemble the wayside? That in the latter case he immediately caught it away; yea, he suffered it not even to take root; but here more of his craft was needed. And these things Christ saith, instructing us to be always wakeful. For, saith He, though thou quite escape those harms, there is yet another harm. For as in those instances "the wayside," and "the rock," and "the thorns," so here again sleep occasions our ruin; so that there is need of continual watchfulness. Something like this took place even at the beginning. Many of the prelates, I mean, bringing into the churches wicked men, disguised heresiarchs, gave great facility to the laying that kind of snare. For the devil needs not even to take any trouble, when he hath once planted them among us. And how is it possible not to sleep? one may say. Indeed, as to natural sleep, it is not possible; but as to that of our moral faculty, it is possible. After this He points out the thing to be superfluous too, not hurtful only; in that, after the land hath been tilled, and there is no need of anything, then this enemy sows again; as the heretics also do, who for no other cause than vainglory inject their proper venom.

And it should be noted that, when He says, Sowed good seed, He intends that good will which is in the elect; when He adds, An enemy came, He intimates that watch should be kept against him; when as the tares grow up, He suffers it patiently, saying, An enemy hath done this, He recommends to us patience; when He says, Lest haply in gathering the tares, &c. He sets us an example of discretion; when He says, Suffer both to grow together till the harvest, He teaches us long-suffering; and, lastly, He inculcates justice, when He says, Bind them into bundles to burn.