"Actually, despite the “extreme a priori” label, praxeology contains one Fundamental Axiom—the axiom of action—which may be called a priori, and a few subsidiary postulates which are actually empirical. Incredible as it may seem to those versed in the positivist tradition, from this tiny handful of premises the whole of economics is deduced — and deduced as absolutely true. Setting aside the Fundamental Axiom for a moment, the empirical postulates are: (a) small in number, and (b) so broadly based as to be hardly “empirical” in the empiricist sense of the term. To put it differently, they are so generally true as to be self-evident, as to be seen by all to be obviously true once they are stated, and hence they are not in practice empirically falsifiable and therefore not “operationally meaningful.” What are these propositions? We may consider them in decreasing order of their generality:
- the most fundamental—variety of resources, both natural and human. From this follows directly the division of labor, the market, etc.
- less important, that leisure is a consumer good.
These are actually the only postulates needed. Two other postulates simply introduce limiting subdivisions into the analysis. Thus, economics can deductively elaborate from the Fundamental Axiom and Postulates (1) and (2) (actually, only Postulate 1 is necessary) an analysis of Crusoe economics, of barter, and of a monetary economy. All these elaborated laws are absolutely true.”
— Murray N. Rothbard, In Defense of Extreme Apriorism