This is the latest in a series of Register articles in which author and syndicated columnist Maggie Gallagher explains love and marriage to her grown son.

“With great power comes great responsibility,” as Spider-Man put it.

Sex is not a mere appetite, whatever the pornographers on Madison Avenue try to persuade you. The power of sex is not only in its procreative potential. But at the most basic level, the power to create new life — human life made in the image of God — has to inspire awe, and a sense of moral seriousness.

With great power comes great responsibility.

Especially when you pause and think for a moment: We are not here talking about the creation of just any human life — immense and wondrous as that is — but your very own child. The person who creates your fatherhood (and fatherhood we know is an attribute of God).

Certainly we have moral obligations to any human being, just by the fact that they are human. But how much more do we owe to our very own children? “Do right by your kids” may not be the highest and noblest aspiration the human soul has ever dreamed up, but surely it is the least that we can expect of any decent man or woman.

So why is it so many people these days find something so basic so very hard?

We live in one of the richest, most creative, powerful and dynamic societies ever seen in all of human history. And yet amidst all this abundance, there is one thing children can no longer count on: the care and concern of their own father.

Nationally, one out of three children is born outside of marriage. Just under half of civil marriages are projected to end in divorce. Scholars now say in scholarly language obvious truths like this Urban Institute policy brief: “Parents who do not live with their children are unlikely to be highly involved in their children's lives.”

Only a minority of children outside of marriage see their fathers as often as once a week. Half of children living outside of intact marriages see their fathers only once a year or less, or never.

Even if fathers don't disappear altogether, when mothers and fathers aren't married to each other, it is hard to be really jointly committed to raising their kids together. Marriage means you and your child's mother will live together, love each other and be sexually faithful. It means you will have children in the future only with each other. Your heart, your money, your body, your home and your kids are all shared.

Being not married means that you and your child's mother live in different houses. Probably different neighborhoods. Eventually, maybe different states, as career and romance and family obligation inexorably diverge. Your money is separate and so are your economic interests. Your relationships with other people are more important that your relationship with each other.

Your moral obligations — not only your tastes, preferences and interests — begin to diverge in ways that make it hard to prioritize the needs of your ex-spouse. In a culture of un-marriage, you will have many loves and other sexual, personal and family relations. You may have other children whose interests diverge radically from your first set.

What marriage unites, un-marriage fragments: sex, love, parenting, money, time, energy, desire and obligation.

What happens to children when marriage no longer holds mothers and fathers together? The hard social science evidence on the consequences for children and society is now compelling.

First, there are the dismal social science casualties: higher rates of poverty, financial hardship, welfare dependency, drug and alcohol abuse, infant mortality, teen suicide, depression, anxiety, unwed motherhood (and fatherhood), sexually transmitted diseases, educational failure (high school drop outs, special education, conduct disorders, being held back a grade), juvenile delinquency and adult criminality.

Beyond that, there is what happens to most children outside of marriage, even those who don't become social-science statistics: the children who lived with stressed-out single mothers, or who compete with stepfathers and new boyfriends for their mom's time, attention and loyalty. The children whose hearts get broken again and again by a father who doesn't seem to love them, to whom they are clearly not even close to the most important thing in his life.

Why do so many people these days find doing right by their kids so hard?

We've separated sex as a concept from what sex actually is. We pretend that sex is just a simple, happy appetite that anyone should be able to indulge, with the right contraceptives. We prioritized the felt needs of adults over those of children. We deny sexual reality to ourselves, and our own children reap the consequences.

Holding together sex, love, care, marriage, money and babies is not easy. Sexual desire is not a simple appetite for pleasure, but a deeply rich and complex passion, one that often presents itself imperiously. When sexual desire is a desire for the whole person, when lust is touched by love, it becomes particularly insistent on its own importance. There is a reason why the ancient Greeks (and many other pagans) imagined Eros as a god, a god of unreason, who attacks with little irresistible arrows without warning.

Which is why making sexual love real, making it not merely about the self, but genuinely about the other, requires an enormous idealistic, heroic and disciplined commitment of reason and emotion, faith and culture.

Today, many adults just aren't willing to make the effort.

Decency says, “If someone has to suffer, it's going to be me, not my kid.” But our sexual culture reverses the formula: “If someone's going to suffer, it's going to be my kids, not me.”

Of course, adults don't say this out loud. They cover it up even from themselves with euphemisms about the inevitability of the death of love, about how children are resilient, which is true, but not a very good excuse for moral callousness about inflicting this kind of suffering on children, especially on our very own children, in order to pursue adult sexual and intimacy needs (and so vainly pursue them, it so often turns out, as adulterous affair follows adulterous affair, or divorce follows divorce).

“If someone's going to suffer, its going to be my kids, not me.” Adultery is one way of saying this. So is divorce. So is abortion. So is engaging in non-marital sex, which does not take the reality of the children you could be making seriously.

The desire for a father comes to a child very early and very powerfully. It has nothing to do with stigma or teasing. It doesn't even necessarily depend on the emotional logic of loss, the grief that comes with an end of an existing attachment (as happens when say, divorcing parents part). A child's longing for his mother and father is in its own way an elemental force. You could get mystical real fast, once you begin to take it seriously.

Here's a story about a boy. Maybe you'll recognize him.

A rather privileged young unwed mom, abandoned by the father of her child (but not her parents, a committed married couple), moves with her son to New York City to take a job as a magazine editor. Like so many young New Yorkers, she cannot afford a whole apartment, so she rents a room in a safe neighborhood. She and her boy have their own, separate living quarters, but share a hallway and kitchen with a complete stranger, the 20-something young man who holds the lease.

It seems innocent enough. Occasionally, they bump into the young man in the hall, but that's all. She has trouble even remembering his name, so little interaction do they have.

After a few months, the young man leaves on vacation for a week or two. Her 5-year-old son suddenly asks, “Mom, where did the man go?”

“I don't know, he's away for a while,” she says, absent-mindedly. Her little boy breaks into wild tears and will not be comforted. So great is his inner need, the boy has mistaken a casual male bystander for a father who will protect and defend him. So great is the undefended longing of one small human heart for fatherhood.

So tell me: Do you have the right to do such a thing to a child, to your own child? How can any decent person claim a right to engage in a sexual union which can have such consequences for his (or her) very own flesh and blood? And for what? For pleasure, loneliness, need, the fleeting satisfaction or frustration of desire?

The first rule of manhood: “If someone has to suffer, it's not going to be my kids. Not if I can help it.”

See where that takes you. With great power … well, you know the rest.

Love, Maggie aka Mom.

Readers who would like to share reactions, anecdotes, their own pressing questions on how to transmit a Catholic vision of marriage to their children, please email Maggie at [email protected].