In a short and remarkable treatise, The Christian Idea of Man, Joseph Pieper explains why prudence is the first of the cardinal virtues, the one that “gives birth” to all the others. His reasoning is clear: “Good presupposes truth, and truth presupposes being.”  Therefore “realization of the good presupposes knowledge of reality,” for “one who does not know how things really are cannot do good; for the good accords with reality.”


Pieper notes that he is not talking about the empirical sciences, but about “real contact with objective reality,” especially as mediated by hearing. For the prudent man is eager to learn from “the genuine knowledge of reality enjoyed by a superior mind,” including the mind of God as revealed in Scripture.

So the prudent man “looks first at reality; and by virtue of and on the basis of his knowledge of reality he decides what is to be done and what not, and how it is to be done and how not.”  Therefore, “all virtue is dependent on prudence,” and every sin is a violation of prudence.

Prudence is sanity in moral action, and sanity, as the schoolmen teach us, is the adaequatio mentis ad rem: the equable adjustment of the mind in concord with the thing.

I know someone who is terrified of birds, no matter how small and harmless. She knows that the sparrow won’t hurt her, and so she understands that her fear is unjustified, and she attempts to fit her actions to the thing. It would be better if she could find delight in the cheerful fellows, but at least she has moved in the direction of sanity.

I know someone else who pretends to have no fear of the Lord, though he ducks and mutters in his pose of atheism. It would be better for him to fear, because the Lord ought to be feared; and his ducking and muttering is a stubbornly healthy remnant of sanity.

The opposite of this adequation is a willed embrace of unreality. We might call it the coercio rei ad phanstasiam: coercing things to accord with your phantasms. These days the phantasms have mostly to do with sex.

Now, it should be easier to go mad over abstractions than over realities that one can notice at a glance. It should be easier to be muddled over patriotism than over whether you are a boy or a girl. It should be easier to stray from the right path when you are trying to figure out what money is, than when you are trying to figure out what a baby is.

The depth of our madness may be fathomed accordingly. It is mad for Walter Mitty to believe that he is a leader of nations; but he has to check his mind and heart and the course of his life to see that he is not. It is madness within madness for him to believe that he is Napoleon. All he has to do then is to check his birth certificate.

So, suppose you have a boy. We’ll call him Jim. Jim is a boy. There’s no doubt about this. A hermaphrodite may have been born ten years ago in Spitzbergen, but for all that, Jim is a boy.

Barring injury or illness, Jim will soon be stronger and faster and more agile than his mother. Soon after that he will be taller than she is, too. His hands and feet will be bigger than hers. His voice will be deeper. His adrenal system will be quicker. His muscles and bones will thicken. All these are facts. We see them every day. 
    

He will bear in his loins the seeds of children. That is a fact. He will become a father in potentia. If his parents and teachers are sane, they will bring him up, day by day, into an adequation of his mind to the reality of his body. Long before he has the man’s form, he will be encouraged to adopt the man’s habits.

        The Allegory of Prudence by Titian (1645)

To see how this works, put Jim on a farm. Someday Jim will have to do the bulk of the harrowing and plowing, the sowing and reaping. He will have to wrestle with the cumbersome machinery and the large domestic animals. So you prepare him for those realities now. You lead him in mind and in habit towards the place where his body will be going. 
    

It is the same for his fatherhood. Jim is a boy. Boys marry girls and become fathers. Those are realities. So you train him up in fatherhood now. Sometimes you talk about it; mostly you show the reality in action. It isn’t a matter of stern determination. It is a matter of loving the boy in him and bringing that boy to manhood. You make manhood a matter of course. 
    

Because Jim bears the seeds of human children, and not of dogs or cats, you open his eyes every day to the reality of marriage. A dog has a life but no history. A cat curls up in the sun and that is her only intimation of eternity. But the human being turns his glance to the limits of the universe itself, and beyond.

Such a creature requires loving parents who turn their glance to the limits of his life, and beyond. That is a fact. 
    

When the time comes for Jim to know about it, his parents will teach him the reality of things: that he carries fatherhood with him, and that he is meant for a love that gives and never retracts. That is no fantasy. Life will be hard, and people are sinners. But a man’s word is his bond. 
    

The alternative is madness, what Pieper defines as ideology: “An unobjective perception of reality dictated by the will.”  It is to compel the world to obey the dictates of that will. It is to people the world with Napoleons.