Gentleness, also known as meekness, mildness, or mansuetude, is, according to Aquinas, the virtue that moderates the passion of anger in accordance with right reason (ST II-II.157). Because it involves a form of restraint or moderation, it is a potential part of temperance, and so is temperance in a broad sense, but it differs from temperance in the strict sense in that it does not deal with desires. While gentleness is not the greatest of virtues, it is very great in a certain respect: anger impedes clear judgment of truth, so there is no virtue more essential to self-possession; for the same reason it removes an important obstacle to coming to know God. Likewise, insofar as gentleness like charity reduces the troubles and evils that others must bear with, it makes us more acceptable to God and neighbor.
Likewise, Hugh Blair has an interesting sermon on gentleness in which he argues that it is a sign of true wisdom (based on James 3:13); he distinguishes gentleness from meekness, with meekness being restraint in anger and gentleness adding to this the positive note of correction of anything offensive in oneself. Gentleness is not the same as passive tameness of spirit, nor is it an unlimited compliance with anything that comes along. It is that virtue, pertaining to charity, that "makes us unwilling to give pain to any of our brethren." It is encouraged by reflecting on what we owe to God, what we share with all human beings, and what our own failings are. Blair also sees gentleness as important for the pursuit of knowledge: it is, he says, the clean air of the mind; the gentle mind is like a smooth stream that reflects the world around in just proportion and vivid color.
For the Christian, gentleness or meekness is one of the virtues especially associated with Christ; Paul in II Cor. 10:1 refers to the gentleness (prautes) and equity (epieikeia) of Christ and Christ himself calls himself gentle (prau) in Mt. 11:29. It is especially associated with his Triumphal Entry (Mt. 21:5). It is one of the beatitudes, insofar as it contributes to happiness, and it is one of the fruits of the spirit, insofar as it arises from the work of the Spirit.