The first book by Hans-Hermann Hoppe that I read was the most excellent Democracy: The God That Failed. In the introduction to that book, Hoppe talks about competing social theories and, in face of conflicting arguments about society or politics or economics, how we can decide between them:
The data of history are logically compatible with… rival interpretations, and historians, insofar as they are just historians, have no way of deciding in favor of one or the other. If one is to make a rational choice among such rival and incompatible interpretations, this is only possible if one has a theory at one’s disposal, or at least a theoretical proposition, whose validity does not depend on historical experience but can be established a priori, i.e. once and for all by means of the intellectual apprehension or comprehension of the nature of things.
In other words, disagreements can’t be solved only by appealing to historical data. In the end “a priori theory trumps and corrects experience (and logic overrules observation), and not vice-versa.” A Theory of Capitalism & Socialism: Economics, Politics, Ethics [full text, pdf] takes this deductive approach. Hoppe starts by building a theory of property. We only need property because things are scarce; where there is no scarcity (e.g. ideas) there is no property…
And the rest flows from that. Sorry I don’t remember much more than that off-hand, because I finished the book almost a year ago. This draft has been sitting neglected for months and months. Just wanted to clear out the archives. Highly recommended, though.