On Marriage and Concupiscence

For the concupiscence of the flesh is in some sort active, even when it does not exhibit either an assent of the heart, where its seat of empire is, or those members whereby, as its weapons, it fulfils what it is bent on. But what in this action does it effect, unless it be its evil and shameful desires? For if these were good and lawful, the apostle would not forbid obedience to them, saying, “Let not sin therefore reign in your mortal body, that you should obey the lusts thereof.” He does not say, that you should have the lusts thereof, but “that you should obey the lusts thereof;” in order that (as these desires are greater or less in different individuals, according as each shall have progressed in the renewal of the inner man) we may maintain the fight of holiness and chastity, for the purpose of withholding obedience to these lusts.

Nevertheless, our wish ought to be nothing less than the nonexistence of these very desires, even if the accomplishment of such a wish be not possible in the body of this death. This is the reason why the same apostle, in another passage, addressing us as if in his own person, gives us this instruction: “For what I would,” says he, “that do I not; but what I hate, that do I.” In a word, “I covet.” For he was unwilling to do this, that he might be perfect on every side. “If, then, I do that which I would not,” he goes on to say, “I consent unto the law that it is good.” Because the law, too, wills not that which I also would not.

For it wills not that I should have concupiscence, for it says, “You shall not covet;” and I am no less unwilling to cherish so evil a desire. In this, therefore, there is complete accord between the will of the law and my own will. But because he was unwilling to covet, and yet did covet, and for all that did not by any means obey this concupiscence so as to yield assent to it, he immediately adds these words: “Now, then, it is no more I that do it, but sin that dwells in me.”