Today’s Catechism sections discuss the vocation to chastity. Supporting material comes from the “Summa Theologica”.
II. The Vocation to Chastity
2337 Chastity means the successful integration of sexuality within the person and thus the inner unity of man in his bodily and spiritual being. Sexuality, in which man's belonging to the bodily and biological world is expressed, becomes personal and truly human when it is integrated into the relationship of one person to another, in the complete and lifelong mutual gift of a man and a woman.
The virtue of chastity therefore involves the integrity of the person and the integrality of the gift.
The integrity of the person
2338 The chaste person maintains the integrity of the powers of life and love placed in him. This integrity ensures the unity of the person; it is opposed to any behavior that would impair it. It tolerates neither a double life nor duplicity in speech.124
2339 Chastity includes an apprenticeship in self-mastery which is a training in human freedom. The alternative is clear: either man governs his passions and finds peace, or he lets himself be dominated by them and becomes unhappy.125 "Man's dignity therefore requires him to act out of conscious and free choice, as moved and drawn in a personal way from within, and not by blind impulses in himself or by mere external constraint. Man gains such dignity when, ridding himself of all slavery to the passions, he presses forward to his goal by freely choosing what is good and, by his diligence and skill, effectively secures for himself the means suited to this end."126
2340 Whoever wants to remain faithful to his baptismal promises and resist temptations will want to adopt the means for doing so: self-knowledge, practice of an ascesis adapted to the situations that confront him, obedience to God's commandments, exercise of the moral virtues, and fidelity to prayer. "Indeed it is through chastity that we are gathered together and led back to the unity from which we were fragmented into multiplicity."127
2341 The virtue of chastity comes under the cardinal virtue of temperance, which seeks to permeate the passions and appetites of the senses with reason.
2342 Self-mastery is a long and exacting work. One can never consider it acquired once and for all. It presupposes renewed effort at all stages of life.128 The effort required can be more intense in certain periods, such as when the personality is being formed during childhood and adolescence.
2343 Chastity has laws of growth which progress through stages marked by imperfection and too often by sin. "Man . . . day by day builds himself up through his many free decisions; and so he knows, loves, and accomplishes moral good by stages of growth."129
2344 Chastity represents an eminently personal task; it also involves a cultural effort, for there is "an interdependence between personal betterment and the improvement of society."130 Chastity presupposes respect for the rights of the person, in particular the right to receive information and an education that respect the moral and spiritual dimensions of human life.
2345 Chastity is a moral virtue. It is also a gift from God, a grace, a fruit of spiritual effort.131 The Holy Spirit enables one whom the water of Baptism has regenerated to imitate the purity of Christ.132
2392 "Love is the fundamental and innate vocation of every human being" (FC 11).
2393 By creating the human being man and woman, God gives personal dignity equally to the one and the other. Each of them, man and woman, should acknowledge and accept his sexual identity.
2394 Christ is the model of chastity. Every baptized person is called to lead a chaste life, each according to his particular state of life.
2395 Chastity means the integration of sexuality within the person. It includes an apprenticeship in self-mastery.
In the “Summa Theologica” (Secunda Secundæ Partis, 151, 1), St. Thomas Aquinas discusses the virtue of chastity.
Article 1. Whether chastity is a virtue?
Objection 1. It would seem that chastity is not a virtue. For here we are treating of virtues of the soul. But chastity, seemingly, belongs to the body: for a person is said to be chaste because he behaves in a certain way as regards the use of certain parts of the body. Therefore chastity is not a virtue.
Objection 2. Further, virtue is "a voluntary habit," as stated in Ethic. ii, 6. But chastity, apparently, is not voluntary, since it can be taken away by force from a woman to whom violence is done. Therefore it seems that chastity is not a virtue.
Objection 3. Further, there is no virtue in unbelievers. Yet some unbelievers are chaste. Therefore chastity is not a virtue.
Objection 4. Further, the fruits are distinct from the virtues. But chastity is reckoned among the fruits (Galatians 5:23). Therefore chastity is not a virtue.
On the contrary, Augustine says (De Decem Chord. [Serm. ix de Tempore]): "Whereas thou shouldst excel thy wife in virtue, since chastity is a virtue, thou yieldest to the first onslaught of lust, while thou wishest thy wife to be victorious."
I answer that, Chastity takes its name from the fact that reason "chastises" concupiscence, which, like a child, needs curbing, as the Philosopher states (Ethic. iii, 12). Now the essence of human virtue consists in being something moderated by reason, as shown above (I-II, 64, 1). Therefore it is evident that chastity is a virtue.
Reply to Objection 1. Chastity does indeed reside in the soul as its subject, though its matter is in the body. For it belongs to chastity that a man make moderate use of bodily members in accordance with the judgment of his reason and the choice of his will.
Reply to Objection 2. As Augustine says (De Civ. Dei i, 18), "so long as her mind holds to its purpose, whereby she has merited to be holy even in body, not even the violence of another's lust can deprive her body of its holiness, which is safeguarded by her persevering continency." He also says (De Civ. Dei i, 18) that "in the mind there is a virtue which is the companion of fortitude, whereby it is resolved to suffer any evil whatsoever rather than consent to evil."
Reply to Objection 3. As Augustine says (Contra Julian. iv, 3), "it is impossible to have any true virtue unless one be truly just; nor is it possible to be just unless one live by faith." Whence he argues that in unbelievers there is neither true chastity, nor any other virtue, because, to wit, they are not referred to the due end, and as he adds (Contra Julian. iv, 3) "virtues are distinguished from vices not by their functions," i.e. their acts, "but by their ends."
Reply to Objection 4. Chastity is a virtue in so far as it works in accordance with reason, but in so far as it delights in its act, it is reckoned among the fruits.
124 Cf. ⇒ Mt 5:37.
125 Cf. ⇒ Sir 1:22.
126 GS 17.
127 St. Augustine, Conf. 10, 29, 40: PL 32, 796.
128 Cf. ⇒ Titus 2:1-6.
129 FC 34.
130 GS 25 # 1.
131 Cf. ⇒ Gal 5:22.
132 Cf. ⇒ 1 Jn 3:3.