Some vulgar or “pop” Austrians make truly absurd claims on the basis of this axiom, such as that all inferences of Austrian economics must be true because they follow from the human action axiom. Not even Mises believed such rubbish:
“Every theorem of praxeology is deduced by logical reasoning from the category of action. It partakes of the apodictic certainty provided by logical reasoning that starts from an a priori category. Into the chain of praxeological reasoning the praxeologist introduces certain assumptions concerning the conditions of the environment in which an action takes place. Then he tries to find out how these special conditions affect the result to which his reasoning must lead. The question whether or not the real conditions of the external world correspond to these assumptions is to be answered by experience. But if the answer is in the affirmative, all the conclusions drawn by logically correct praxeological reasoning strictly describe what is going on in reality” (Mises 1978: 44).In other words, praxeology relies on deduction and requires premises that are sometimes synthetic propositions, not ones true a priori.
The human action axiom says that all voluntary human action (by sane, non-mentally ill humans, of course!) is “purposeful,” and this is used in the early deductions of praxeology.
Can anyone see the problem here? I think it is very clear.
The human action axiom is a trivial observation that can also be held by Marxists, communists, Keynesians, neoclassicals, monetarists, or any other economist you care to name. And there is nothing significant you can deduce from it without other premises, since the most simple, useful deductive argument like the syllogism requires 2 premises to infer anything.
Moreover, as even Mises noted, once you get into praxeological arguments they quickly come to use synthetic propositions – either present or hidden – that can only be verified empirically (see “Mises’ Praxeology: A Critique,” October 1, 2010). Thus empirical evidence becomes very relevant indeed.
The “apodictic certainty” claimed for praxeology actually vanishes like a puff of smoke, if there is doubt about the truth of its synthetic stated and hidden assumptions or premises. And there certainly is. One example I have dealt with before is the argument for free trade by comparative advantage (see “Mises on the Ricardian Law of Association: The Flaws of Praxeology,” January 25, 2011).
The correct response to Austrians making idiotic claims about the human action axiom is this: you tell us what you can deduce from only one axiom. Do tell us - we’re fascinated...
Yet another problem with praxeology should be clear to anyone who has read Mises’ Human Action: it is a long, rambling book where it often unclear which arguments are Mises’ ranting and which ones are supposed to be praxeological arguments with apodictic certainty arrived at by deduction. Mises uses informal verbal arguments to lay out his deductions. If he were really a first-rate logician, then Mises would have set his arguments out formally, as was pointed out a long time ago by George J. Schuller:
“Acceptance of Mises’ stated axioms does not necessarily imply acceptance of the “principles” or “applications to reality” which he has drawn from them, even though his logic may be impeccable. When a logical chain grows beyond the limits set by stated assumptions, it uses unstated assumptions. The number of unstated assumptions (axioms, postulates, or other) in Human Action is enormous. If Mises denies this, let him try to rewrite his book as a set of numbered axioms, postulates, and syllogistic inferences using, say, Russell’s Principia or, closer home, Von Neumann’s Theory of Games as a model” (Schuller 1951: 188).Addendum: Quine’s Philosophy is a Disaster for Praxeology
Another point is that any Austrian who adopts Quine’s idea that there is no meaningful distinction between analytic or synthetic propositions has destroyed the basis for the a priori status of the human action axiom. For Quine believed that no proposition is immune from possible revision of its truth by the test of experience and that there is in fact no real a priori knowledge of reality.
Mises, L. 1978 . The Ultimate Foundation of Economic Science: An Essay on Method (2nd edn, Sheed Andrews & McMeel, Kansas City.
Schuller, G. J. 1951. “Mises’ ‘Human Action’: Rejoinder,” American Economic Review 41.1: 185–190.