Don Boudreaux on the law and legislation:
In fact, law is, as the great Harvard legal scholar Lon Fuller defined it, ”the enterprise of subjecting human conduct to the governance of rules.”* This enterprise requires neither that rules be written down nor enacted by a sovereign. Murder and thievery are just two of many activities that were against the law - and punished severely - long before any legislature or monarch first wrote down proscriptions against them.
It is a serious error to mistake legislation for law. The two are not the same.
Read more here.