The need for law is the need to make a man a certain kind of man; to make a society a certain kind; to make a system a certain kind. It says that the man, or the system, has a potential/tendency to decay, deteriorate, or dissipate energy wastedly; to attain to an undesirable state, one that flows from the opposite of truth or the accepted facts.
What are we really doing when we make laws for our children and ourselves?
Every law that the government produces makes a statement, not just of what is legal, but also of what we should aspire to: how it wants us to be. Law is a codification of the ethics (imposed rules) of our existence, citizenship, and residence.
The purpose of law is to make the perfect man; the purpose of law is to make the ideal citizen; the purpose of law is to make the ideal society. But the ideal does not exist where the law exists, otherwise there would be no need for law.
If full love ruled, then perfection would be real. Husbands, fully love your wives, and wives, your husbands. (Love for your children is implicit in loving your spouse.) Imperfect people leading ideal lives.
So the law functions to train one’s conscience. Your conscience is the arbiter of personal convictions. Convictions which may be of truth, or falsehood in the guise of facts or feelings. The law trains us, like the media tries to do.