In order to combat positivist methodology in economics, Mises attempted a Kantian turn in his understanding of praxeology. He tried to do for economic laws what Kant did for the laws of logic, space and time, and the Newtonian understanding of the cosmos.
So construed, according to Mises, we can have apodictic certainty of the laws of economics without needing to introduce empirical methods into the practice of praxeology and catallactics.
This becomes problematic, however, if we consider the other axiomatic statement of the Misesian paradigm, which is that all humans act according to purposeful and free action. If man is entirely free to act according to their will, then the apodictic certainty must be qualified with a ceteris paribus clause, which negates the previous certainty allegedly discovered within the logical formalism of praxeology. That is, if we must qualify the certainty to which humans act, there is only an instrumental “certainty” as a result.
Additionally, this Kantian move was meant to overcome the mechanistic mathematical determinism Mises thought existed in the Neo-Classical positivist framework of Milton Friedman’s method. However, the Kantian move fails to undermine this perceived problem because it is itself a form of mechanistic determinism. For Kant, and therefore Mises, the transcendental apparatus which forms the external world is determined by the concepts of the mind, to which the same would apply for the laws of economics on the Misesian view. Far from undermining the positivist framework, Mises merely restates the problem in a different way.
– Lucas G. Westman