What is that all about? What kind of political economic philosophy is libertarian anarcho-capitalism? The non-cognoscenti may need a road map.  Let us break this down into three parts.

First libertarianism. What is that? It is a theory of just law. One foundation is the Non-Aggression Principle (NAP): it would be a crime to initiate violence against anyone or his property. Thus, justified aspects of the law would prohibit murder, rape, theft, arson, kidnapping, fraud, etc. But we need a theory of justice in property to determine whether or not a forced transfer of goods is justified or not. It is if the act is one of returning stolen property, otherwise it is illicit. How, then, to determine justice in property rights? We start off with the primordial basic premise that we all own ourselves; we are self-owners. Then, when we mix our labor with the land, homestead it a la John Locke, we become its rightful owners. Property titles are just, also, if they are predicated upon any voluntary interaction. John clears some virgin land and grows corn on it. Peter domesticates a cow and obtains milk. Then they barter. John now owns the milk even though he did not produce it, ditto for Peter and the corn. But they can each trace their ownership to homesteading and agreed upon contract. Other licit transfers would include buying, selling, gambling, gift-giving, investing, lending, borrowing, etc.

There are several levels of libertarianism based on the degree of adherence to these two principles. At the lowest level is the classical liberalism of such figures as Milton Friedman, Friedrich Hayek, and James Buchanan. They favor free enterprise, to be sure, but they also allow for all sorts of government intervention into the economy. For example, involving support for the Fed (instead of free enterprise money), school vouchers (instead of full educational privatization), a small amount of welfare (e.g., the negative income tax), anti-trust regulation, etc.  A closer observance of the NAP would be the constitutionalism of Ron Paul, who would very strictly interpret this document. But, since in addition to armies, police, and courts, it allows for governmental highways, streets, and a post office, it is not as lean and mean as the minimal government libertarianism of advocates such as Ayn Rand and Robert Nozick, who only allow for the first three aforementioned functions.