Law, Property Rights, and Air Pollution pdf by Murray Rothbard
Law is a set of commands; the principles of tort or criminal law, which we shall be dealing with, are negative commands or prohibitions, on the order of “thou shalt not” do actions X, Y, or Z. In short, certain actions are considered wrong to such a degree that it is considered appropriate to use the sanctions of violence (since law is the social embodiment of violence) to combat, defend against, and punish the transgressors.
There are many actions against which it is not considered appropriate to use violence, individual or organized. Mere lying (that is, where contracts to transfer property titles are not broken), treachery, base ingratitude, being nasty to one’s friends or associates, or not showing up for appointments, are generally considered wrong, but few think of using violence to enjoin or combat them. Other sanctions, such as refusing to see the person or have dealings with him, putting him in Coventry, and so on, may be used by individuals or groups, but using the violence of the law to prohibit such actions is considered excessive and inappropriate.
If ethics is a normative discipline that identifies and classifies certain sets of actions as good or evil, right or wrong, then tort or criminal law is a subset of ethics identifying certain actions as appropriate for using violence against them. The law says that action X should be illegal, and therefore should be combated by the violence of the law. The law is a set of “ought” or normative propositions.