Today’s Catechism sections discuss purity. Supporting material comes from the “Summa Theologica”.

II. The Battle for Purity

2520 Baptism confers on its recipient the grace of purification from all sins. But the baptized must continue to struggle against concupiscence of the flesh and disordered desires. With God's grace he will prevail
- by the virtue and gift of chastity, for chastity lets us love with upright and undivided heart;
- by purity of intention which consists in seeking the true end of man: with simplicity of vision, the baptized person seeks to find and to fulfill God's will in everything;312
- by purity of vision, external and internal; by discipline of feelings and imagination; by refusing all complicity in impure thoughts that incline us to turn aside from the path of God's commandments: "Appearance arouses yearning in fools";313
- by prayer:

I thought that continence arose from one's own powers, which I did not recognize in myself. I was foolish enough not to know . . . that no one can be continent unless you grant it. For you would surely have granted it if my inner groaning had reached your ears and I with firm faith had cast my cares on you.314

2521 Purity requires modesty, an integral part of temperance. Modesty protects the intimate center of the person. It means refusing to unveil what should remain hidden. It is ordered to chastity to whose sensitivity it bears witness. It guides how one looks at others and behaves toward them in conformity with the dignity of persons and their solidarity.

2522 Modesty protects the mystery of persons and their love. It encourages patience and moderation in loving relationships; it requires that the conditions for the definitive giving and commitment of man and woman to one another be fulfilled. Modesty is decency. It inspires one's choice of clothing. It keeps silence or reserve where there is evident risk of unhealthy curiosity. It is discreet.

2523 There is a modesty of the feelings as well as of the body. It protests, for example, against the voyeuristic explorations of the human body in certain advertisements, or against the solicitations of certain media that go too far in the exhibition of intimate things. Modesty inspires a way of life which makes it possible to resist the allurements of fashion and the pressures of prevailing ideologies.

2524 The forms taken by modesty vary from one culture to another. Everywhere, however, modesty exists as an intuition of the spiritual dignity proper to man. It is born with the awakening consciousness of being a subject. Teaching modesty to children and adolescents means awakening in them respect for the human person.

2525 Christian purity requires a purification of the social climate. It requires of the communications media that their presentations show concern for respect and restraint. Purity of heart brings freedom from widespread eroticism and avoids entertainment inclined to voyeurism and illusion.

2526 So called moral permissiveness rests on an erroneous conception of human freedom; the necessary precondition for the development of true freedom is to let oneself be educated in the moral law. Those in charge of education can reasonably be expected to give young people instruction respectful of the truth, the qualities of the heart, and the moral and spiritual dignity of man.

2527 "The Good News of Christ continually renews the life and culture of fallen man; it combats and removes the error and evil which flow from the ever-present attraction of sin. It never ceases to purify and elevate the morality of peoples. It takes the spiritual qualities and endowments of every age and nation, and with supernatural riches it causes them to blossom, as it were, from within; it fortifies, completes, and restores them in Christ."315

IN BRIEF

2532 Purification of the heart demands prayer, the practice of chastity, purity of intention and of vision.

2533 Purity of heart requires the modesty which is patience, decency, and discretion. Modesty protects the intimate center of the person.

In the “Summa Theologica”, (Secunda Secundæ Partis, 151, 4), St. Thomas Aquinas discusses the relationship between purity and chastity.

Article 4. Whether purity belongs especially to chastity?

Objection 1. It would seem that purity does not belong especially to chastity. For Augustine says (De Civ. Dei i, 18) that "purity is a virtue of the soul." Therefore it is not something belonging to chastity, but is of itself a virtue distinct from chastity.

Objection 2. Further, "pudicitia" [purity] is derived from "pudor," which is equivalent to shame. Now shame, according to Damascene [De Fide Orth. ii, 15, is about a disgraceful act, and this is common to all sinful acts. Therefore purity belongs no more to chastity than to the other virtues.

Objection 3. Further, the Philosopher says (Ethic. iii, 12) that "every kind of intemperance is most deserving of reproach." Now it would seem to belong to purity to avoid all that is deserving of reproach. Therefore purity belongs to all the parts of temperance, and not especially to chastity.

On the contrary, Augustine says (De Perseverantia xx): "We must give praise to purity, that he who has ears to hear, may put to none but a lawful use the organs intended for procreation." Now the use of these organs is the proper matter of chastity. Therefore purity belongs properly to chastity.

I answer that, As stated above (Objection 2), "pudicitia" [purity] takes its name from "pudor," which signifies shame. Hence purity must needs be properly about the things of which man is most ashamed. Now men are most ashamed of venereal acts, as Augustine remarks (De Civ. Dei xiv, 18), so much so that even the conjugal act, which is adorned by the honesty [Cf. 145] of marriage, is not devoid of shame: and this because the movement of the organs of generation is not subject to the command of reason, as are the movements of the other external members. Now man is ashamed not only of this sexual union but also of all the signs thereof, as the Philosopher observes (Rhet. ii, 6). Consequently purity regards venereal matters properly, and especially the signs thereof, such as impure looks, kisses, and touches. And since the latter are more wont to be observed, purity regards rather these external signs, while chastity regards rather sexual union. Therefore purity is directed to chastity, not as a virtue distinct therefrom, but as expressing a circumstance of chastity. Nevertheless the one is sometimes used to designate the other.

Reply to Objection 1. Augustine is here speaking of purity as designating chastity.

Reply to Objection 2. Although every vice has a certain disgrace, the vices of intemperance are especially disgraceful, as stated above (Question 142, Article 4).

Reply to Objection 3. Among the vices of intemperance, venereal sins are most deserving of reproach, both on account of the insubordination of the genital organs, and because by these sins especially, the reason is absorbed.

Footnotes

312 Cf. ⇒ Rom 12:2; ⇒ Col 1:10.
313 ⇒ Wis 15:5.
314 St. Augustine, Conf. 6, 11, 20: PL 32, 729-730.
315 GS 58 # 4.