Mises versus Ayer on Analytic Propositions and a priori Reasoning

Actually, the analysis below reveals that Mises appears to have misunderstood the logical positivist position to some degree, and that Mises does indeed need synthetic a priori knowledge for praxeology.

First, let us look at this crucial passage from Human Action on analytic a priori inference:

“Aprioristic reasoning is purely conceptual and deductive. It cannot produce anything else but tautologies and analytic judgments. All its implications are logically derived from the premises and were already contained in them. Hence, according to a popular objection, it cannot add anything to our knowledge.

All geometrical theorems are already implied in the axioms. The concept of a rectangular triangle already implies the theorem of Pythagoras. This theorem is a tautology, its deduction results in an analytic judgment. Nonetheless nobody would contend that geometry in general and the theorem of Pythagoras in particular do not enlarge our knowledge. Cognition from purely deductive reasoning is also creative and opens for our mind access to previously barred spheres. The significant task of aprioristic reasoning is on the one hand to bring into relief all that is implied in the categories, concepts, and premises and, on the other hand, to show what they do not imply. It is its vocation to render manifest and obvious what was hidden and unknown before. ….

The real thing which is the subject matter of praxeology, human action, stems from the same source as human reasoning. Action and reason are congeneric and homogeneous; they may even be called two different aspects of the same thing. That reason has the power to make clear through pure ratiocination the essential features of action is a consequence of the fact that action is an offshoot of reason. The theorems attained by correct praxeological reasoning are not only perfectly certain and incontestable, like the correct mathematical theorems. They refer, moreover, with the full rigidity of their apodictic certainty and incontestability to the reality of action as it appears in life and history. Praxeology conveys exact and precise knowledge of real things.” (Mises 2008: 38–39).

So Mises, in the first paragraph, is asserting that aprioristic reasoning “cannot add anything to our knowledge,” according to a “popular” objection, which is a reference to the logical positivism that dominated philosophy in the post-1945 era in Europe and America.

But that was not the logical positivist view at all. To see this, we need only look at the crucial passage of A. J. Ayer’s Language, Truth and Logic (1936; 2nd edn. 1946):

“When we say that analytic propositions are devoid of factual, content, and consequently that they say nothing, we are not suggesting that they are senseless in the way that metaphysical utterances are senseless. For, although they give us no information about any empirical situation, they do enlighten us by illustrating the way in which we use certain symbols. Thus if I say, ‘Nothing can be coloured in different ways at the same time with respect to the same part of itself’, I am not saying anything about the properties of any actual thing; but I am not talking nonsense. I am expressing an analytic proposition, which records our determination to call a colour expanse which differs in quality from a neighbouring colour expanse a different part of a given thing. In other words, I am simply calling attention to the implications of a certain linguistic usage. Similarly, in saying that if all Bretons are Frenchmen, and all Frenchmen Europeans, then all Bretons are Europeans, I am not describing any matter of fact. But I am showing that in the statement that all Bretons are Frenchmen, and all Frenchmen Europeans, the further statement that all Bretons are Europeans is implicitly contained. And I am thereby indicating the convention which governs our usage of the words ‘if’ and ‘all’.

We see, then, that there is a sense in which analytic propositions do give us new knowledge. They call attention to linguistic usages, of which we might otherwise not be conscious, and they reveal unsuspected implications in our assertions and beliefs.” (Ayer 1971 [1936]: 73–74).

We see here that the logical positivist view, as held by Ayer, is that analytic a priori propositions are

(1) not meaningless or nonsense as “metaphysical” propositions were presumed to be;

(2) did have real meaning and sense, and

(3) could and do provide human beings with “new knowledge,” such as revealing “unsuspected implications in our assertions and beliefs.”

In sense (3), then, not even A. J. Ayer denied that a priori reasoning from analytic statements can yield new knowledge: what Ayer was denying was that analytic a priori reasoning gives us necessarily true knowledge of the real, external world.

So Mises was wrong: his positivist opponents did not claim that a priori inference with analytic statements adds nothing to human knowledge.

What they did claim is that a priori reasoning did not yield necessarily true knowledge of the real world. But here Mises clearly disagrees:

“The real thing which is the subject matter of praxeology, human action, stems from the same source as human reasoning. Action and reason are congeneric and homogeneous; they may even be called two different aspects of the same thing. That reason has the power to make clear through pure ratiocination the essential features of action is a consequence of the fact that action is an offshoot of reason. The theorems attained by correct praxeological reasoning are not only perfectly certain and incontestable, like the correct mathematical theorems. They refer, moreover, with the full rigidity of their apodictic certainty and incontestability to the reality of action as it appears in life and history. Praxeology conveys exact and precise knowledge of real things.” (Mises 2008: 38–39).

According to Mises, praxeological reasoning yields

(1) “apodictic certainty and incontestability to the reality of action as it appears in life and history,” and

(2) praxeology “conveys exact and precise knowledge of real things.”

Epistemologically speaking, the only way it can do this is to either

(1) be Kantian synthetic a priori knowledge, or

(2) be the functional and epistemological equivalent of Kantian synthetic a priori knowledge (even if Mises chose not to use the term synthetic a priori explicitly).

But the idea that Mises never linked his epistemology to Kant is utterly untrue.

Why? The reason is that the very term “category” comes from Kant, and Mises’s idea of a “category of action” was clearly inspired by Kantian a priori categories:

“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.” (Mises 1978: 44).

“Following in the wake of Kant’s analyses, philosophers raised the question: How can the human mind, by aprioristic thinking, deal with the reality of the external world? As far as praxeology is concerned, the answer is obvious. Both, a priori thinking and reasoning on the one hand and human action on the other, are manifestations of the human mind. The logical structure of the human mind creates the reality of action. Reason and action are congeneric and homogeneous, two aspects of the same phenomenon.” (Mises 1978 [1962]: 42).

In the last passage, from Mises’s The Ultimate Foundation of Economic Science: An Essay on Method (1962), he is explicitly linking his “category of action” to Kant’s philosophy.

I see no way around this conclusion.

Further Reading
“Mises on Kant and Praxeology,” September 15, 2013.

“Barrotta’s Kantian Critique of Mises’s Epistemology,” July 28, 2013.

BIBLIOGRAPHY
Ayer, A. J. 1971 [1936]. Language, Truth and Logic. Penguin Books, London.

Mises, Ludwig von. 1978 [1962]. The Ultimate Foundation of Economic Science: An Essay on Method (2nd edn), Sheed Andrews & McMeel, Kansas City.

Mises, Ludwig von. 2008. Human Action: A Treatise on Economics. The Scholar’s Edition. Mises Institute, Auburn, Ala.