But, if you be so minded, we will bring before you the language of those who wrest these declarations. For this will make our own statements clearer. For there are some that say, that he is not here saying what he does of the Law of Moses, but some take it of the law of nature; some, of the commandment given in Paradise. Yet surely Paul's object everywhere is to annul this Law, but he has not any question with those. And with much reason; for it was through a fear and a horror of this that the Jews obstinately opposed grace. But it does not appear that he has ever called the commandment in Paradise “Law” at all; no, nor yet any other writer. Now to make this plainer from what he has really said, let us follow out his words, retracing the argument a little. Having then spoken to them about strictness of conversation, he goes on to say, “Do you not know, brethren, how that the Law has dominion over a man as long as he lives? Wherefore you have become dead to the Law.” Therefore if these things are said about the natural law, we are found to be without the natural law. And if this be true, we are more senseless than the creatures which are without reason. Yet this is not so, certainly. For with regard to the law in Paradise, there is no need to be contentious, lest we should be taking up a superfluous trouble, by entering the lists against things men have made up their minds upon. In what sense then does he say, “I should not have known sin but by the Law?” He is speaking, not of absolute want of knowledge, but of the more accurate knowledge. For if this were said of the law of nature, how would what follows suit? “For I was alive,” he says, “without the Law once.” Now neither Adam, nor any body else, can be shown ever to have lived without the law of nature. For as soon as God formed him, He put into him that law of nature, making it to dwell by him as a security to the whole kind (Gr. Nature, see p. 365). And besides this, it does not appear that he has anywhere called the law of nature a commandment. But this he calls as well a commandment, and that “just and holy,” as a “spiritual law.” But the law of nature was not given to us by the Spirit. For barbarians, as well as Greeks and other men, have this law. Hence it is plain, that it is the Mosaic Law that he is speaking of above, as well as afterwards, and in all the passages. For this cause also he calls it holy, saying, “Wherefore the Law is holy, and the commandment holy, and just, and good.” For even though the Jews have been unclean since the Law, and unjust and covetous, this does not destroy the virtue of the Law, even as their unbelief does not make the faith of God of none effect. So from all these things it is plain, that it is of the Law of Moses that he here speaks.
Ver. 13. “Was then that which is good made death unto me? God forbid. But sin that it might appear sin.” (4 manuscripts om. ἡ.)
That is, that it might be shown what great evil sin is, namely, a listless will, an inclinableness to the worse side, the actual doing (3 manuscripts om. this clause), and the perverted judgment. For this is the cause of all the evils; but he amplifies it by pointing out the exceeding grace of Christ, and teaching them what an evil He freed the human race from, which, by the medicines used to cure it, had become worse, and was increased by the preventives. Wherefore he goes on to say: “That sin, by the commandment, might become exceeding sinful.” Do you see how these things are woven together everywhere? By the very means he uses to accuse sin, he again shows the excellency of the Law. Neither is it a small point which he has gained by showing what an evil sin is, and unfolding the whole of its poison, and bringing it to view. For this is what he shows, by saying, “that sin by the commandment might become exceeding sinful.” That is, that it may be made clear what an evil sin is, what a ruinous thing. And this is what was shown by the commandment. Hereby he also shows the preëminence of grace above the Law, the preëminence above, not the conflict with, the Law. For do not look to this fact, that those who received it were the worse for it; but consider the other, that the Law had not only no design of drawing wickedness out to greater lengths, but even seriously aimed at hewing down what already existed. But if it had no strength, give to it indeed a crown for its intention, but adore more highly the power of Christ, which abolished, cut away: and plucked up the very roots an evil so manifold and so hard to be overthrown. But when you hear me speak of sin, do not think of it as a substantial power, but evil doing, as it comes upon men and goes from them continually, and which, before it takes place, has no being, and when it has taken place, vanishes again. This then was why the Law was given. Now no law is ever given to put an end to things natural, but in order to correct a way of acting purposely wicked. And this the lawgivers that are without too are aware of, and all mankind in general. For it is the evils from viciousness alone that they are for setting right, and they do not undertake to extirpate those allotted us along with our nature; since this they cannot do. For things natural remain unalterable (Arist. Eth. b. 2, c. 1), as we have told you frequently in other discourses also.
Source: Homilies on Romans (New Advent)