When parents, in raising their children, deny them something they would like to do, it is not uncommon for the children to ask why they cannot follow the latest trend, or spend hours surfing the internet or playing computer games. The first answer can often be simply “because we can’t afford it,” or “because you need to finish your homework,” or what may be a better answer, “because you will end up a slave to your whims.”
Up to a point these are all valid replies, at least for getting out of a momentary predicament. But they could also have the unintended result of clouding the beauty of the virtue of temperance, making it appear in the children’s eyes as a simple negation of what attracts them.
In contrast, temperance, like any other virtue, is fundamentally affirmative. It permits a person to become a master of oneself and puts order into one’s emotions and affections, likes and desires, and the most intimate tendencies of the ‘I.’ In short, it ensures equilibrium in the use of material goods and helps one to aspire to a higher good.  Thus St. Thomas Aquinas places temperance at the very root of both the sensitive and spiritual life.  In fact, if we read the beatitudes attentively we see that, in one way or another, almost all of them are related to this virtue. Without it one cannot see God, nor be consoled, nor inherit the earth and heaven, nor bear injustice patiently.  Temperance channels the forces of the human heart to put into practice all the virtues.
Christianity is not limited to saying that pleasure is “permitted.” Rather pleasure is viewed as a positive good, since God himself has made it part of human nature, the result of satisfying our tendencies. But this is compatible with the awareness that original sin exists, and has brought disorder to our passions. We all understand why St. Paul says, I do the evil that I do not want.  It is as though evil and sin have been inserted into the human heart, which, after the Fall, has to defend itself against itself. Here the role of temperance is clearly revealed, namely protecting and orientating the human person’s interior order.
One of the first points of the The Way helps situate the place of temperance in the life of men and women: “Get used to saying no.”  St. Josemaria, when explaining the meaning of this point to his confessor, said that “it is easier to say yes: to ambition, to the senses.…”  In a get-together he remarked that “ when we say yes, everything is easy. But when we have to say No, we are confronted with a struggle, and sometimes defeat, not victory, is the outcome of that struggle. So we have to get used to saying No to win in this struggle, because from this internal victory comes peace, and the peace you bring into your homes—into the homes of each one of you—and into society and the whole world.” 
Saying “no” often brings with it an interior victory that is the source of peace. It means denying ourselves something that separates us from God—the ambitions of our ego, our disordered passions…. And it is indispensable for affirming our own freedom, and for taking a stance in and towards the world.
When someone says “yes” to everyone and everything that seems attractive, he falls into a mechanistic way of acting and in some sense “depersonalizes” himself, becoming like a puppet moved by the will of others. Perhaps we have known such a person, unable to say “no” to the impulses from the environment or to the desires of those around him. They are flatterers whose apparent spirit of service proves to be a lack of character or even hypocrisy, people who are unable to complicate their life with a “no.”
A person who says “yes” to everything ultimately shows that outside himself everything else has little importance for him. On the other hand, the one who knows he bears a treasure in his heart,  sees the need to struggle against whatever is opposed to it. Therefore to say “no” to some things is, above all, to commit oneself to other goods; it is to situate oneself in the world, to affirm before others one’s own scale of values, one’s personal way of being and acting. In the end, it means wanting to forge one’s character, to commit oneself to what one truly values and make it known by one’s own actions.
The expression “well-tempered” is often used to express the idea of solidity, consistency. “Temperance is self-mastery”—a self-mastery that is achieved when one is aware that “not everything we experience in our bodies and souls should be given free reign. Not everything that we can do should be done. It is easier to let ourselves be carried way by so-called natural impulses; but this road ends up in sadness and isolation in our own misery.” 
One ends up dependent on external stimuli, seeking happiness in deceptive, fleeting sensations that can never satisfy us. The intemperate person can never find peace; he swerves from one object to another and ends up trapped in an endless search that becomes an authentic flight from himself. He is always dissatisfied, living as though unable to accept his situation, as though he always needed to seek ever new sensations.
In few vices is slavery to sin more clearly seen than in intemperance. As the Apostle says, they have given themselves up in despair to sensuality.  The intemperate person seems to have lost self-control, bent on seeking ever new sensations and pleasures. In contrast, temperance numbers among its fruits serenity and calm. It neither silences nor denies the desires and passions, but makes one a true master of oneself. Peace, which is “the tranquility of order,”  is only found in a heart that is sure of itself and prepared to give itself.
Temperance and moderation
How can one teach others the virtue of temperance? St. Josemaria often raised this question, and underlined two key ideas: fortitude in one’s own example, while always fostering people’s freedom. He said that parents should teach their children “to live temperately, to lead a somewhat ‘spartan,’ that is, Christian, life. It’s hard but you have to be courageous: have the courage to teach them austerity. If not, you won’t accomplish anything.” 
In first place, parents need to be courageous in order to personally lead a life of Christian austerity. Precisely because it is a virtue whose acts are directed to detachment, those being educated need to see its good effects. If parents through their temperate lives radiate cheerfulness and peace of soul, their children will have an incentive to imitate them. The simplest and most natural way of transmitting this virtue is within the family, above all when children are still young. If they see their parents renounce with good humor what is viewed as a caprice, or sacrifice their own rest to care for the family (for example, helping the children with their homework, bathing and feeding the youngest ones, or playing with them), they will grasp the meaning of these actions and their importance to the home environment.
In second place, courage is also needed to hold up the virtue of temperance as a desirable good and lifestyle. Certainly, when the parents live a temperate life it is easier to pass on this virtue to their children. But at times the doubt may arise whether they are interfering in the legitimate freedom of their children, or “imposing” on them, without any right to do so, their own way of living. They might even question whether it is effective to ask their children to refrain from something when they have no desire to do so. By denying them a whim, won’t the desire for it remain or even strengthen, especially when their friends have it? They could come to feel ‘discriminated against’ in their relationship with their peers. Or even worse, it could be an occasion for them to distance themselves from their parents and be insincere.
But if we are realistic, we will come to see that none of these objections are really convincing. By living temperately, one discovers that temperance is a good, and that it is not a matter of unreasonably imposing an insupportable burden on children, but rather of preparing them for life. As St. Josemaria insisted, an austere life is a Christian life. Temperance is an essential virtue whereby we put some order into the chaos that original sin has introduced into human nature.
It is a virtue that everyone has to struggle to acquire if they wish to be masters of themselves. Therefore we have to know how to explain why the virtue should be lived and how to provoke situations in which it can be exercised. And, when the occasion arises, we need to know how to resist (asking our Lord for the strength to do so) the caprices that arise from the environment and the child’s desires—which are only natural but are already tainted by an incipient concupiscence.
Freedom and temperance
When all is said and done, it is question of raising children both for temperance and freedom at the same time. These two spheres can never be separated, since freedom permeates a person’s entire being and is the very foundation of all education. Education is directed to helping each person freely make the correct decisions that will shape his or her life.
This process is not assisted by a protective attitude in which, for all practical purposes, the parents end up supplanting the will of the child and controlling each and every movement; nor by an excessively authoritarian attitude that leaves no room for the growth of the child’s personality and own judgment. These approaches lead in the end to a “substitute” for ourselves or a person without character.
The right approach is to permit children to make their own decisions in a way that is in keeping with their age, and to teach them to learn to choose by making them see the consequences of their actions. At the same time, they need to sense the support of their parents—and of all those involved in their education—in order to choose correctly, or when need be, to rectify an erroneous decision.
An event from St. Josemaria’s own childhood is illustrative here. His parents refused to give in to his whims, and when he was given something to eat he didn’t like, his mother wouldn’t prepare anything else for him. Until one day the young boy threw the dish of food he didn’t like against the wall. His parents left the stain on the wall for some months, so he could see clearly the consequences of his action. 
The attitude of St. Josemaria’s parents shows us how to harmonize respect for a child’s freedom with the necessary fortitude so as not to compromise with what is merely a caprice. Certainly the way to solve each situation will differ. In raising children, there are no easy recipes applicable to everyone; the important thing is to find what is best for each child and be clear, because one has experienced this in one’s own life, about what values should be taught and loved and about what could prove harmful. In any case, it is best to foster the principle of respect for freedom; it is preferable to err in some cases rather than to always impose one’s own judgment; even more so when the children perceive it to be unreasonable or even arbitrary.
This small anecdote from St. Josemaria’s life focuses attention on one of the key areas for teaching the virtue of temperance: during meals. Everything done to foster good manners and moderation at meals helps children to acquire this virtue.
It is true that each stage in life presents specific circumstances that require formation to be given in different ways; for example adolescence will require greater discretion in social relations, while also permitting parents to articulate more fully the reasons for acting in one way or another. But temperance in meals can be taught right from infancy with relative ease, giving the child the fortitude and self-mastery that will be of such great use when the time comes to struggle with temperance in adolescence.
Thus, for example, preparing a variety of menus, watching out for caprices or whims, encouraging children to finish food they don’t especially like, not leaving food on the plate, teaching the correct use of cutlery, or insisting that no one starts eating before everyone has been served, are all specific ways of strengthening the child’s will. During infancy, moreover, the family environment of temperance—courageous temperance!—that the parents try to live is transmitted as if by osmosis to the children, without anything special needing to be done.
If left over food isn’t thrown out but used to prepare other dishes; if the parents don’t eat between meals, and wait till the others have seconds of a desert that is particularly appealing, the children come to consider such behavior as natural. At the opportune moment, reasons for behaving like this can be given to them, in a way they can understand: so as to be generous and show affection for one’s brothers and sisters, or to offer a small sacrifice to Jesus.… Reasons that children frequently understand much better than adults think.
J.M. Martin and J. de la Vega
 Cf. Catechism of the Catholic Church , 1809.
 Cf. St. Thomas Aquinas, S. Th. II-II, q. 141, aa. 4, 6.
 Cf. Mt 5:3-11.
 Rom 7:19.
 The Way , 5.
 St.Josemaria, Handwritten text, in The Way . Critical-historical edition, 5.
 St. Josemaria, Notes taken in a get-together, 28 October 1972.
 Cf. Mt 6:21.
 St. Josemaria, Friends of God , no. 84.
 Eph 4:19.
 St. Augustine, De civtate Dei , 19, 13.
 St. Josemaria, Get-together in Barcelona, 28 November 1972.
 Cf. Andres Vazquez de Prada, The Founder of Opus Dei , Scepter, vol. 1, p. 19.