The harmlessness of the mission performed by law and lawful defense is self-evident; the usefulness is obvious; and the legitimacy cannot be disputed.
As a friend of mine once remarked, this negative concept of law is so true that the statement, the purpose of the law is to cause justice to reign, is not a rigorously accurate statement. It ought to be stated that the purpose of the law is to prevent injustice from reigning. In fact, it is injustice, instead of justice, that has an existence of its own. Justice is achieved only when injustice is absent.
But when the law, by means of its necessary agent, force, imposes upon men a regulation of labor, a method or a subject of education, a religious faith or creed -- then the law is no longer negative; it acts positively upon people. It substitutes the will of the legislator for their own wills; the initiative of the legislator for their own initiatives. When this happens, the people no longer need to discuss, to compare, to plan ahead; the law does all this for them. Intelligence becomes a useless prop for the people; they cease to be men; they lose their personality, their liberty, their property.
Try to imagine a regulation of labor imposed by force that is not a violation of liberty; a transfer of wealth imposed by force that is not a violation of property. If you cannot reconcile these contradictions, then you must conclude that the law cannot organize labor and industry without organizing injustice.