This is chapter 10 of St. Thomas' work On the Perfection of the Spiritual Life. The book's primary aim is to consider the religious life and priesthood, etc., but much of it can be applied to the ordinary lay Christian as well. In this work, St. Thomas lists three different ways by which one might attain perfection. In this particular passage, he speaks of the third way, namely self-denial. This is especially relevant now in the season of Lent.
The Third Way to Perfection, Which is the Denial of Our Own Will
It is not only necessary for the perfection of charity that a man should sacrifice his exterior possessions: he must also, in a certain sense, relinquish himself. Dionysius, in De Divinis Nominibus IV, says that, “divine love causes a man to be out of himself, meaning thereby, that this love suffers him no longer to belong to himself but to Him whom he loves.”St. Paul, writing to the Galatians, illustrates this state by his own example, saying, “I live, now not I, but Christ lives in me” (Gal 2:20), as if he did not count his life as his own, but as belonging to Christ, and as if he spurned all that he possessed, in order to cleave to Him. He further shows that this state reaches perfection in certain souls; for he says to the Colossians, “For you are dead, and your life is hidden with Christ in God” (Col 3:3). Again, he exhorts others to the same sublimity of love, in his second Epistle to the Corinthians, “And Christ died for all, that they also who live, may not now live to themselves, but unto Him who died for them, and rose again” (2 Cor 5:15). Therefore, when our Lord had said, “If any man comes to me, and does not hate his father, and mother, and wife, and children, and brethren, and sisters,” He added something greater than all these, saying, “yes, and his own life also, he cannot be my disciple” (Luke 14:26). He teaches the same thing in the Gospel of St. Matthew when He says, “If any man would come after me, let him deny himself and take up his cross and follow Me” (Mat 16:24).
This practice of salutary self-abnegation, and charitable self-hatred, is, in part, necessary for all men in order to salvation, and is, partly, a point of perfection. As we have already seen from the words of Dionysius quoted above, it is in the nature of divine love that he who loves should belong, not to himself, but, to the one beloved. It is necessary, therefore, that self-abnegation and self-hatred be proportionate to the degree of divine love existing in an individual soul. It is essential to salvation that a man should love God to such a degree, as to make Him his end, and to do nothing which be believes to be opposed to the Divine love. Consequently, self-hatred and self-denial are necessary for salvation. Hence St. Gregory says, in his Homily, “We relinquish and deny ourselves when we avoid what we were wont (through the old man dwelling in us) to be, and when we strive after that to which (by the new man) we are called.” In another homily he likewise says, “We hate our own life when we do not condescend to carnal desires, but resist the appetites and pleasures of the flesh.”
But in order to attain perfection, we must further, for the love of God, sacrifice what we might lawfully use, in order, thus to be more free to devote ourselves to Him. It follows, therefore, that self-hatred, and self-denial, pertain to perfection. We see that our Lord speaks of them as if they belonged to it. For, just as in the Gospel of St. Matthew he says, “If you would be perfect, go, sell all that you have and give to the poor,” (Mat 19:21) but does not lay any necessity on us to do so, leaving it to our own will, so He likewise says, “if any man would come after Me, let him deny himself, and take up his cross, and follow Me” (Matt. 16:24). St. Chrysostom thus explains these words, “Christ does not make his saying compulsory; He does not say, ‘whether you like it or not, you must bear these things.’” In the same manner, when He says: “If any man will come after Me and hate not his father” etc. (Luke 14:28), He immediately asks, “Which of you having a mind to build a tower, does not first sit down, and reckon the charges that are necessary, whether) he have enough to finish it?” St. Gregory in his Homily thus expounds these words, “The precepts which Christ gives are sublime, and, therefore, the comparison between them and the building of a high tower shortly follows them.” And he says again, “That young man could not have had enough to finish his tower who, when he heard the counsel to leave all things, went away sad.” We may hence understand, that these words of our Lord refer, in a certain manner, to a counsel of perfection.
The martyrs carried out this counsel of perfection most perfectly. Of them St. Augustine says (in his sermon De martyribus, that “none sacrifice so much as those who sacrifice themselves.” The martyrs of Christ, denying themselves, did, in a certain manner, hate their lives, for the love of Christ. St. Chrysostom, again, says, writing on the Gospel of St. Matthew, “He who denies another, be it his brother, or his servant, or whomsoever it may be, will not assist him if he sees him suffering from the scourge or any other torture. And we, in like manner, ought to have so little regard for our body, that, if men should scourge, or in any other way maltreat, us, we ought not to spare ourselves.”
Our Lord would not have us to think that we are to deny ourselves, only so far as to endure insults and hard words. He shows us that we are to deny ourselves unto death, even unto the shameful death of the cross. For He says: “Let him take up his cross and follow Me.” We, therefore, say that the martyrs did a most perfect work; for they renounced, for the love of God, life itself, which others hold so dear, that, for its sake, they are content to part with all temporal goods, and are willing to purchase it by any sacrifice whatsoever. For a man will prefer to lose friends and wealth, and to suffer sickness, or even slavery, rather than to be deprived of life. Conquerors will grant to their defeated foes the privilege of life, in order that they may keep them subject to them in slavery. Satan said to the Lord, “Skin for skin, and all that a man has he will give for life” (Job 2:4), i.e. to preserve his body.
Now, the more dearly a thing is loved according to nature, the more perfect it is to despise it, for the sake of Christ. Nothing is dearer to any man than the freedom of his will, whereby he is lord of others, can use what he pleases, can enjoy what he wills, and is master of his own actions. Just, therefore, as a person who relinquishes his wealth, and leaves those to whom be is bound by natural ties, denies these things and persons; so, he who renounces his own will, which makes him master, does truly deny himself. Nothing is so repugnant to human nature as slavery; and, therefore, there is no greater sacrifice (except that of life), which one man can make for another, than to give himself up to bondage for the sake of, that other. Hence, the younger Tobias said to the angel, “if I should give myself to be your servant, I should not make a worthy return for your care” (Tobit 9:2).
Some men deprive themselves, for the love of God, of some particular use of their free will, binding themselves by vow, to do, or not to do, some specific thing. A vow imposes a certain obligation on him that makes it; so that, for the future, he is not at liberty to do, or not to do, what was formerly permissible to him; for he is bound to accomplish his vow. Thus, we read in Ps. 65. 13, “I will pay you my vows which my lips have uttered,”and again, “If you have vowed anything to God, defer not to pay it; for an unfaithful and foolish promise displeases him” (Eccles. 5:3).
Others there are, however, who make a complete sacrifice of their own will, for the love of God, submitting themselves to another by the vow of obedience, of which virtue Christ has given us a sublime example. For, as we read in the Epistle to the Romans, “As by the disobedience of one man, many were made sinners; so also by the obedience of one, many shall be made just” (Rom 5:19). Now this obedience consists in the denial of our own will. Hence, our Lord said, “Father, if it be possible, let this chalice pass from Me: nevertheless not as I will but as you will” (Matt. 26:39). Again He said, “I came down from Heaven, not to do my own will, but the will of Him who sent Me” (John 6:38). By these words He shows us, that, as He renounced His own will, submitting it to the Divine will, so we ought wholly to subject our will to God, and to those whom He has set over us as His ministers. To quote the words of St. Paul, "obey your prelates and be subject to them" (Heb. 13:17).