There is a popular slogan in modern politics, often shouted by libertarians and progressives alike: "You cannot legislate morality!" It is used as a shield against any law that touches on the deeper questions of human life -- marriage, bioethics, or the definition of the person. The implication is that the Law should be a moral vacuum, concerned only with "harm" and "consent," while leaving questions of Good and Evil to the private conscience.

But this slogan is a lie. It is a philosophical absurdity that dissolves the moment we examine what a law actually is.

The Inescapability of the Good

All law is the imposition of a moral order. A law is essentially a statement that says: "This behavior is good for the community, and that behavior is bad."

Consider the laws against racial discrimination. Why do we have them? Because we have made a moral judgment that racism is an evil. We are "policing the sin" of racism because we believe it harms the dignity of the person.

Consider the laws against animal cruelty. Why do we punish a man for beating his dog? The dog cannot vote. It pays no taxes. We punish the man because we have a collective moral conviction that cruelty to sentient beings is a vice that degrades our society.

If we truly stopped "policing morality," we would have to repeal almost every law on the books. We would be left with a jungle where the only rule is the survival of the fittest.

The Distinction Between Sin and Crime

However, the critic is right to fear a State that tries to police every sin. This is where the wisdom of the Christian tradition saves us from the extremes of both theocracy and libertinism.

St. Thomas Aquinas taught that while all law is moral, not all morality should be law. He distinguished between Divine Law (which governs the heart) and Human Law (which governs the public square).

The State has no business policing your thoughts, your private prayers, or your minor vices, provided they do not harm the Common Good. The law does not punish you for being jealous, or for lying to your spouse, or for being greedy. These are sins, yes. But if the State tried to punish them, it would become a totalitarian nightmare.

Human Law exists to secure the "public peace." It focuses on those external acts that are necessary for society to function. Murder. Theft. Perjury. The violation of contracts.

The Pedagogy of Law

But here is the nuance we must not miss. While the law cannot forbid every vice, it must still point toward the Good.

The Law is a teacher (a pedagogue). It shapes the conscience of the citizen. If the law permits something, the citizens eventually come to believe it is moral. When the law permitted slavery, many people stopped seeing the humanity of the slave. When the law permits no-fault divorce, people eventually stop believing in the permanence of marriage.

Therefore, we legislate morality not to force people to be saints -- that is the work of grace -- but to create a "habitat" where virtue is possible. We create laws that protect the family, the child, and the weak because these laws teach us what a human being is.

The Myth of Neutrality

The modern secularist claims to want a "neutral" public square. But notice what happens when they claim to banish "religious morality." They immediately replace it with their own.

They impose new laws on speech, new mandates on education, and new definitions of the family. They are quite happy to "police sins" -- the sins of intolerance, or misgendering, or environmental negligence.

They are not against legislating morality. They are simply against legislating Christian morality. They want to replace the morality of Freedom for Excellence (which aligns with nature) with the morality of Freedom of Indifference (which worships the will).

We must have the courage to say that neutrality is impossible. We must choose. We can have laws based on the objective truth of the human person, or we can have laws based on the raw power of the state to define reality. But we cannot have an empty square.