In Catholic moral philosophy, modesty is closely connected to the cardinal virtue of temperance (also called moderation or self-control). Temperance is one of the four cardinal virtues (prudence, justice, fortitude, and temperance) and governs our appetites and desires, ensuring they remain ordered and not excessive.

This relates even to permitted enjoyments or licit pleasures or activities (e.g. things that are not bad in of and themselves but by excess become sinful). For instance, conversation becomes bad when it is excessive, cynical, ironical, and irritating. Dieting become sinful when it results in anorexia. Alcohol is considered harmful when done to excess (like, historically, smoking and, today, vaping).

Dress and manner can likewise become intemperate.

The Catechism of the Catholic Church:

1809 Temperance is the moral virtue that moderates the attraction of pleasures and provides balance in the use of created goods.

… Keep love whole through temperance. It follows God, and is careful in thought to avoid deceit and trickery (prudence) …

"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." (CCC 2521–2522)

The intemperate person does not know when to stop. He bewilders and concerns others. He is the model of bitter zeal (James 3:14 yet, if you have bitter zeal, and rivalry in your heart, do not glory, nor lie against the truth). Instead of winning people, he only frustrates and burns them out. In a sense, the intemperate man might be ignorant confusing vice for virtue - by believing that the good lies in excess, extremism, uncharity (Romans 10:2, “they have a zeal for God, but not according to knowledge”). The answer lies in temperance, wisdom and knowledge.

St. Thomas Aquinas, whose treatment in the Summa Theologiae (II-II, q. 160) notes that temperance can be seen to moderate sensual desires and pleasures such as food and drink. Those virtues are abstinence (against excessive eating and drinking) and chastity (against hyper-sexuality).

Modesty: the Outward (Virtue) Face of Temperance

Modesty pertains to outward appearance and humbleness (Micah 6:8 - Mankind, he has told each of you what is good and what it is the Lord requires of you: to act justly, to love faithfulness, and to walk humbly with your God.)

Our bearing, speech, appearance, attitude all require moderation to avoid excessive and exhbitionistic behavior.

From temperance and a well-ordered life (the good life we seek) we also develop modesty which protects our chastity and humility by preventing excess.

vanity, exhibitionism, self-importance, vain-glory, provocative or obscene behavior, or drawing inappropriate attention to oneself opposed to humility, decorum, and respect

Just as too little clothing is problematic, so is too much without context. One who dresses inappropriately attracts unnecessary attention and the gaze of others by being histrionic. Modesty does not mean women and men are not allowed to invest appropriate time and energy into their attire (e.g. what they will wear) and be pleasing to others and company by creativity and ingenuity (e.g. appropriate fashion & appropriate costume). 1 Corinthians 10:31 “Therefore, whether you eat or drink, or whatever you do, do all things for the glory of God.”

The under-dressed person can be immodest and so can the overly-dressed person. The root cause is the same. The Church warns against sinful attitudes toward clothing or using clothing (or lack thereof) to promote sin (intent/context). It does not forbid appropriate fashion, socializing, costume and theatre.

“My yoke is easy and my burden is light" (Matthew 11:30). Moral theology should not be unreasonable. “The forms taken by modesty vary from one culture to another.” — Catechism of the Catholic Church 2524. This means that how modesty is expressed in dress and behavior can look different depending on local customs, climate, and social norms, even though the virtue of modesty itself is constant and grounded in human dignity and chastity. Even a Muslim woman can uncover her hair, arms, and legs at home and around family - all these can be uncovered. Fr. Prummer's Handbook of Moral Theology said great care is required regarding context particularly to avoid upsetting delicate & tender consciences who might see sin where there is none.

Modesty isn't limited to clothing. It includes:

• Interior modesty — humility, avoiding pride or exaggerated self-importance.

• Exterior modesty — reasonable restraint in dress, gestures, laughter, speech, recreation, and social presentation.

• Avoiding both extremes: shamelessness (excess) and excessive bashfulness (defect).

We must not confuse temperance with quietism, indifference, laziness or sloth. Rather temperance concerns harmful excess. Zealousness is praiseworthy, while reckless disregard for the rights and feelings of others is not (1 Corinthians 8:9 Be careful, however, that your freedom does not become a stumbling block to the weak.)

It is not cowardice (vs. pride and excessive ambition), timidness (vs. brazen disregard) weakness (vs. boastful pride of life 1 John 2:16) to refuse to engage in behavior that is intemperate. Instead, it is prudent (wise), considerate (loving & patient) and pleasing to God (trusting and faithful).

In sum, it might all really be down to common-sense. We know we ought not harm ourselves and others through irresponsible behavior. The negative thoughts that goad us on to self-destruction or self-harm need to be processed appropriately to avoid acting on them. Call this temperance, call this virtue, or simply being a good person. We should all know, recognize and feel what this is. It is simply behaving appropriately and doing what’s right.