Objection 1. It would seem that there cannot be virtue and vice in connection with outward apparel. For outward adornment does not belong to us by nature, wherefore it varies according to different times and places. Hence Augustine says (De Doctr. Christ. iii, 12) that "among the ancient Romans it was scandalous for one to wear a cloak with sleeves and reaching to the ankles, whereas now it is scandalous for anyone hailing from a reputable place to be without them." Now according to the Philosopher (Ethic. ii, 1) there is in us a natural aptitude for the virtues. Therefore there is no virtue or vice about such things.
Objection 2. Further, if there were virtue and vice in connection with outward attire, excess in this matter would be sinful. Now excess in outward attire is not apparently sinful, since even the ministers of the altar use most precious vestments in the sacred ministry. Likewise it would seem not to be sinful to be lacking in this, for it is said in praise of certain people (Hebrews 11:37): "They wandered about in sheepskins and in goatskins." Therefore it seems that there cannot be virtue and vice in this matter.
Objection 3. Further, every virtue is either theological, or moral, or intellectual. Now an intellectual virtue is not conversant with matter of this kind, since it is a perfection regarding the knowledge of truth. Nor is there a theological virtue connected therewith, since that has God for its object; nor are any of the moral virtues enumerated by the Philosopher (Ethic. ii, 7), connected with it. Therefore it seems that there cannot be virtue and vice in connection with this kind of attire.
On the contrary, Honesty [Cf. 145] pertains to virtue. Now a certain honesty is observed in the outward apparel; for Ambrose says (De Offic. i, 19): "The body should be bedecked naturally and without affectation, with simplicity, with negligence rather than nicety, not with costly and dazzling apparel, but with ordinary clothes, so that nothing be lacking to honesty and necessity, yet nothing be added to increase its beauty." Therefore there can be virtue and vice in the outward attire.
I answer that, It is not in the outward things themselves which man uses, that there is vice, but on the part of man who uses them immoderately. This lack of moderation occurs in two ways. First, in comparison with the customs of those among whom one lives; wherefore Augustine says (Confess. iii, 8): "Those offenses which are contrary to the customs of men, are to be avoided according to the customs generally prevailing, so that a thing agreed upon and confirmed by custom or law of any city or nation may not be violated at the lawless pleasure of any, whether citizen or foreigner. For any part, which harmonizeth not with its whole, is offensive." Secondly, the lack of moderation in the use of these things may arise from the inordinate attachment of the user, the result being that a man sometimes takes too much pleasure in using them, either in accordance with the custom of those among whom he dwells or contrary to such custom. Hence Augustine says (De Doctr. Christ. iii, 12): "We must avoid excessive pleasure in the use of things, for it leads not only wickedly to abuse the customs of those among whom we dwell, but frequently to exceed their bounds, so that, whereas it lay hidden, while under the restraint of established morality, it displays its deformity in a most lawless outbreak."
In point of excess, this inordinate attachment occurs in three ways. First when a man seeks glory from excessive attention to dress; in so far as dress and such like things are a kind of ornament. Hence Gregory says (Hom. xl in Ev.): "There are some who think that attention to finery and costly dress is no sin. Surely, if this were no fault, the word of God would not say so expressly that the rich man who was tortured in hell had been clothed in purple and fine linen. No one, forsooth, seeks costly apparel" (such, namely, as exceeds his estate) "save for vainglory." Secondly, when a man seeks sensuous pleasure from excessive attention to dress, in so far as dress is directed to the body's comfort. Thirdly, when a man is too solicitous [Cf. 55, 6] in his attention to outward apparel.
Accordingly Andronicus [De Affectibus] reckons three virtues in connection with outward attire; namely "humility," which excludes the seeking of glory, wherefore he says that humility is "the habit of avoiding excessive expenditure and parade"; "contentment" [Cf. 143, Objection 4], which excludes the seeking of sensuous pleasure, wherefore he says that "contentedness is the habit that makes a man satisfied with what is suitable, and enables him to determine what is becoming in his manner of life" (according to the saying of the Apostle, 1 Timothy 6:8): "Having food and wherewith to be covered, with these let us be content;"--and "simplicity," which excludes excessive solicitude about such things, wherefore he says that "simplicity is a habit that makes a man contented with what he has."
In the point of deficiency there may be inordinate attachment in two ways. First, through a man's neglect to give the requisite study or trouble to the use of outward apparel. Wherefore the Philosopher says (Ethic. vii, 7) that "it is a mark of effeminacy to let one's cloak trail on the ground to avoid the trouble of lifting it up." Secondly, by seeking glory from the very lack of attention to outward attire. Hence Augustine says (De Serm. Dom. in Monte ii, 12) that "not only the glare and pomp of outward things, but even dirt and the weeds of mourning may be a subject of ostentation, all the more dangerous as being a decoy under the guise of God's service"; and the Philosopher says (Ethic. iv, 7) that "both excess and inordinate defect are a subject of ostentation."
Reply to Objection 1. Although outward attire does not come from nature, it belongs to natural reason to moderate it; so that we are naturally inclined to be the recipients of the virtue that moderates outward raiment.
Reply to Objection 2. Those who are placed in a position of dignity, or again the ministers of the altar, are attired in more costly apparel than others, not for the sake of their own glory, but to indicate the excellence of their office or of the Divine worship: wherefore this is not sinful in them. Hence Augustine says (De Doctr. Christ. iii, 12): "Whoever uses outward things in such a way as to exceed the bounds observed by the good people among whom he dwells, either signifies something by so doing, or is guilty of sin, inasmuch as he uses these things for sensual pleasure or ostentation."
Likewise there may be sin on the part of deficiency: although it is not always a sin to wear coarser clothes than other people. For, if this be done through ostentation or pride, in order to set oneself above others, it is a sin of superstition; whereas, if this be done to tame the flesh, or to humble the spirit, it belongs to the virtue of temperance. Hence Augustine says (De Doctr. Christ. iii, 12): "Whoever uses transitory things with greater restraint than is customary with those among whom he dwells, is either temperate or superstitious." Especially, however, is the use of coarse raiment befitting to those who by word and example urge others to repentance, as did the prophets of whom the Apostle is speaking in the passage quoted. Wherefore a gloss on Matthew 3:4, says: "He who preaches penance, wears the garb of penance."
Reply to Objection 3. This outward apparel is an indication of man's estate; wherefore excess, deficiency, and mean therein, are referable to the virtue of truthfulness, which the Philosopher (Ethic. ii, 7) assigns to deeds and words, which are indications of something connected with man's estate.
Source: Summa Theologica (New Advent)