Here is the masterful essay on property rights that represents Murray Rothbard's most advanced thought. It is probably the most seminal of all pieces on the topic that have appeared in our times.

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.1 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.