Thomas Aquinas

After the Apostle has shown in what the state of spiritual life consists — namely, that it consists in charity — he consequently here deals with the cause of that state, namely the Holy Spirit, whom he says must be followed. Here he sets down a threefold benefit of the Holy Spirit. The first of these is liberation from the servitude of the flesh; the second is liberation from the servitude of the law; and the third is the conferring of life, or security from the damnation of death. The second is given where he says, "But if you are led," etc. The third, where he says, "If we live by the spirit," etc. Concerning the first he does two things. First he sets down the first benefit of the Spirit; second he shows the necessity of this benefit, where he says, "For the flesh," etc.

He says therefore: I say that you ought through charity to serve one another by the Spirit, because nothing profits without charity. But I say this: "in Christ," that is, through faith in Christ, "walk by the spirit," that is, by mind and reason. For sometimes our mind is called "spirit," according to that word of Ephesians 4: "be renewed in the spirit of your mind"; and 1 Corinthians 4: "I will sing with the spirit, I will sing also with the mind." Or, "walk by the spirit," that is, make progress by the Holy Spirit through good working. For the Holy Spirit moves and instigates hearts to work well. Romans 8:14: "who are led by the Spirit of God," etc. One must walk, therefore, by the spirit, that is, by the mind, so that reason or the mind itself may agree with the law of God, as is said in Romans 7:16. For the human spirit is of itself vain, and unless it is ruled from elsewhere, it wavers this way and that, as is said in Sirach 34:6: "and as the heart of one in labor conceives fantasies unless a visitation has been sent from the Most High," etc. Whence of certain men it is said in Ephesians 4:17: "they walk in the vanity of their sense," etc. Human reason, therefore, cannot stand perfectly, except insofar as it is made right by the divine Spirit. And therefore the Apostle says, "walk by the spirit," that is, through the Holy Spirit ruling and leading, whom we ought to follow as one showing the way. For the knowledge of the supernatural end is not ours except from the Holy Spirit. 1 Corinthians 2:9: "eye has not seen, nor ear heard, nor has it entered into the heart of man," etc., and it continues: "but to us God has revealed it through his Spirit." Likewise as one inclining us. For the Holy Spirit instigates, and inclines the affection to willing well. Romans 8:14: "who are led by the Spirit of God," etc. Psalm 142:10: "your good spirit shall lead me into the right land." Now one must walk by the spirit for this reason: because it frees from the corruption of the flesh. Whence it follows, "and you shall not fulfill the desires of the flesh," that is, the delights of the flesh, which the flesh suggests. This the Apostle desired, saying in Romans 7:24: "unhappy man that I am, who shall deliver me from the body of this death? The grace of God," etc. And afterward he concludes in the eighth chapter: "there is therefore now no condemnation to those who are in Christ Jesus, who walk not according to the flesh." The reason for this he subjoins in the same place, saying: "for the law of the spirit of life in Christ Jesus has freed me from the law," etc. And this is the special desire of the saints, that they not fulfill the desires to which the flesh instigates — yet in such a way that under this are not included the desires that pertain to the necessity of the flesh, but those that pertain to superfluity.

Consequently, when he says, "for the flesh lusts," etc., he sets down the necessity of this benefit, which arises from the mutual assault of flesh and spirit. And first he sets down the assault itself; second he manifests it through a clear sign, where he says, "for these are contrary to one another," etc. He says therefore: it is necessary that through the spirit you overcome the desires of the flesh. For "the flesh lusts against the spirit." But here there seems to be a difficulty, since, since to lust is an act of the soul alone, it does not seem to belong to the flesh. To this it must be said, according to Augustine, that the flesh is said to lust insofar as the soul, by means of the flesh itself, lusts — just as the eye is said to see, though it is rather the soul that sees through the eye. Thus, then, the soul lusts through the flesh when it seeks after those things which are delightful according to the flesh. But the soul lusts of itself when it is delighted in those things which are according to the spirit, such as the works of the virtues and the contemplation of divine things and the meditation of wisdom. Wisdom 6:21: "the desire of wisdom, therefore, leads to an everlasting kingdom," etc.

But if the flesh lusts through the spirit, how does it lust against it? In this, namely, that the concupiscence of the flesh impedes the concupiscence of the spirit. For since the delightful things of the flesh are goods that are below us, while the delightful things of the spirit are goods that are above us, it happens that when the soul is occupied about the lower things, which are of the flesh, it is drawn back from the higher things, which are of the spirit.

But there seems to be a difficulty also about what he says, namely, that "the spirit lusts against the flesh." For if we here take "spirit" for the Holy Spirit, and the concupiscence of the Holy Spirit is against evils, it seems to follow that the flesh, against which the spirit lusts, is evil, and thus the error of the Manichean follows. I respond. It must be said that the spirit does not lust against the nature of the flesh, but against its desires, namely those which are for superfluity. Whence also it was said above: "the desires of the flesh," namely the superfluous ones, "you shall not fulfill." For in necessary things the spirit does not contradict the flesh, since, as is said in Ephesians 5:29, "no man ever hated his own flesh."

Consequently, when he says, "for these," etc., he sets down the sign of the mutual conflict, as if he were saying: it is clear by experience that they fight against one another and are contrary, to such an extent that "not whatsoever things you will" — namely, good or evil — "you do," that is, you are permitted to do. Romans 7:19: "for the good which I will, I do not, but," etc.

Nevertheless free choice is not thereby taken away. For since free choice consists in this, that it has election, freedom of choice is found in those things which fall under election. But not all the things that are in us are simply subject to our choice, but only in a certain respect. For in a particular instance I can avoid this or that movement of concupiscence or of anger, but in general we cannot avoid all movements of anger or concupiscence, and this on account of the corruption of the tinder introduced from the first sin.

But it should be noted that there are four kinds of men with respect to concupiscences, of whom none does whatsoever he wills. For the intemperate, who out of set purpose follow the carnal passions, according to that word of Proverbs 2:14, "who rejoice when they have done evil," do indeed do what they will, insofar as they follow those very passions; but insofar as their own reason murmurs against it and it displeases them, they do what they do not will. The incontinent, however, who have the purpose of abstaining, and yet are overcome by the passions, do indeed do what they do not will, insofar as they follow those very passions against their own purpose; and thus the intemperate do more of what they will. The continent, however, who would wish altogether not to lust, do what they will while they do not lust; but because they cannot altogether not lust, they do what they do not will. The temperate, on the other hand, do indeed what they will, insofar as, the flesh being tamed, they do not lust; but because it cannot be tamed entirely so that it does not in some measure resist the spirit — just as neither can malice grow so great that reason does not murmur against it — therefore, when at some time they do lust, they do what they do not will, yet more of what they will.