... classifiedina two-fold way:On the onehandthey are either analyticorsynthetic, and on the otherthey are either a prioriora posteriori. The mean-ing of these distinctions is, in short, the following. ... understanding of action; and that the status of economicsasasort of applied logic derivesfrom the status of the action-axiomasan apriori-truesyntheticproposition. The laws of exchange, the ... economictheorems-like the law of marginalutili~or the law of returns,or the time-preference theory of interest and the Austrian business cycletheory-canbe given definite proof,suchthatitcan...