I decided to read Hans-Hermann Hoppe’s Economic Science And The Austrian Method (1995) in order to grasp a deeper philosophical understanding of the Austrian School’s methodology of economic inquiry. I was especially interested in Immanuel Kant’s influence on Ludwig von Mises and how Mises had used Kant’s epistemological insights to construct praxeology, the study of human action (economics included) that is purely deductive in nature.

Those who are acquainted with scientific methodologies in the field of economics may have heard of the controversies surrounding praxeology. Living in an empirical age, many people may be inclined to question the validity of a science that claims to arrive at economic laws from pure deduction whose validity can be established independently from observations. Praxeological propositions are indeed much more “like those of logic and mathematics, a priori” (Mises, 1966, p. 32). Such a science may strike the skeptics as being disquietly dogmatic.

In this book review, I will firstly give a brief discussion why it is important at all to discuss the epistemological foundations of economic science. Thereafter, I will discuss Hoppe’s thesis. I will describe the philosophical aspects of praxeology that can be traced back to Kantian epistemology. I will moreover summarize Hoppe’s critique of empiricism and historicism, and why Mises believed that economics is essentially praxeology. Lastly, I will give my personal thoughts on the book.

Why should we discuss the epistemological foundations of economic science?
The most immediate answer to this question is that different epistemological foundations lead to different methodologies and different theories, which can lead to different interpretations of real-life phenomena. Take for example the interpretation of an historical economic event, the Great Depression. Murray Rothbard, because he is working within the context of praxeology makes use of the praxeological Austrian Business Cycle Theory. This theory focuses on the expansion of the money supply as an explanation of the onset of the ‘boom’ in the 1920’s which eventually resulted in the ‘bust’ in 1929. Milton Friedman and Anna Schwartz in A Monetary History Of The United States (1963), while not applying the ABCT, have focused only on the contraction of the money supply and the resulting higher interest rates in 1928 as the main cause of the Great Depression. Their application of different economic methods has led them to look for different possible historical causes of the Great Depression which has effectively resulted in different accounts of the same historical event. It therefore matters what economic methods are employed in economic research.

Now that we have established the importance of inquiring epistemological foundations and methodologies of economic science, I will turn to Hoppe’s thesis.

Kant and synthetic a priori propositions
Working within the rationalist tradition of Leibniz and Kant, Mises attempts to present the proper way through which economic science – a science that according to Mises falls within the broader science of human action, praxeology – should be conducted. He resorts to the Kantian conception of the nature of knowledge and explains praxeology in terms of Kantian terminology. Hence, Hoppe firstly directs the reader to Kantian epistemology.

Kant had developed the idea that all propositions are either analytic or synthetic and either a priori or a posteriori. The difference between analytic and synthetic propositions is that the former is true by virtue of their meaning or as Kant would have phrased it himself, “the predicate B belongs to the subject A as something that is (covertly) contained in this concept A” (Kant, 1781, A:6-7). Take for instance the following proposition: “Bachelors are unmarried.” This proposition is analytic, because the predicate, ‘unmarried’, is part of the concept of a bachelor. Analytic propositions are regarded as tautological propositions; they simply restate the definition or a concept incorporated within a word and therefore they do not tell us anything meaningful about the world. A synthetic proposition on the other hand is a proposition whose predicate concept is not contained in the subject’s concept. It could therefore express something meaningful about the world. An example of a synthetic proposition is: “All bachelors are unhappy.” The concept ‘unhappy’ is not contained within the definition of ‘bachelor’, and expresses something meaningful about ‘bachelors’.

The distinction between a priori and a posteriori is as follows: a priori propositions are propositions whose justification does not rely upon experience, but solely on logical reasoning. The justifications of a posteriori propositions on the other hand, do rely upon experience. Examples of a posteriori propositions are “Some bachelors I have met are unhappy” or “Siddharta Gautama left the palace.”

The big question is: do synthetic a priori propositions exist? Kant certainly believed that they do exist, “and it is because Mises subscribes to this claim that he can be called a Kantian” (Hoppe, 1995, p. 18). In Critique of Pure Reason (1781), Kant contended that synthetic a priori propositions do exist and as an example he took mathematics (Kant, 1781, p. 55). The statement “7 + 5 = 12” is not dependent on experimentation and the concept 12 is not contained in either the definitions of 7 or 5. According to Kant, a priori propositions are derived from self-evident axioms. We can find such axioms by reflecting upon ourselves and understanding ourselves as knowing subjects. However, how can truth claims derived from reflection in our mind have any basis in reality? Is Kant here running into the problem of idealism – a notion that it is the mind that constructs reality and superimposes itself upon reality in such a way that it fits within the mind’s necessary laws?

According to Hoppe, Kant had not given a satisfactory response to this issue and future thinkers would have to take on the challenge of solving this problem. Hoppe believes that Mises had done so successfully when he had averred that action provides the link between mind – body and between mind – external world: “[W]e must recognize that such necessary truths are not simply categories of our mind, but that our mind is one of acting persons. Our mental categories have to be understood as ultimately grounded in categories of action” (Hoppe, 1995, p. 20). It is through action that the mind and reality are related: “[A]cting is a cognitively guided adjustment of a physical body in physical reality” (Hoppe, 1995, p. 70).

Another issue that arises with regards to the possibility of synthetic a priori propositions, and which I have found quite confusing myself is the following: does Hoppe suggest that we can arrive at knowledge without any experience of ourselves or the external world at all? No, according to Hoppe “the truth of a priori synthetic propositions derives ultimately from inner, reflectively produced experience” (Hoppe, 1995, p. 19). This experience is phrased by Stolyarov II as “the mind’s identification of facts about actually existing entities, including the identifier himself” (Stolyarov II, 2007, p. 53). In this sense, the action axiom is experientially-derived, but it is not subjected to the empiricists’ narrow view that all knowledge must be testable, verifiable, or falsifiable.

Empiricism, Historicism, and Praxeology
When Mises systematically constructed the foundations of praxeology, he faced a double-challenge; (A) empiricism which was quickly becoming the main influence in the economics discipline, and (B) historicism which was then a prevailing ideology at German-speaking universities.

(A) Empiricism
Empiricism is the “philosophy which thinks of economics and the social sciences in general as following the same logic of research of that, for instance, of physics” (Hoppe, 1995, p. 28). Hoppe writes that empiricism is governed by the following two related basic propositions:

(1) that empirical knowledge, knowledge about reality, must be subjected to falsifiability and verifiability by observational experience;
(2) and that empiricist research formulates their explanations in terms of causality, i.e. “if A, then B”. (Hoppe, 1995, pp. 28-29)

Hoppe continues to write that the validity of empirical statements

can never be established with certainty… The statement will always be and always remain hypothetical… Should experience confirm a hypothetical causal explanation, this would not prove that the hypothesis was true. Should one observe an instance where B indeed followed A as predicted, it verifies nothing… Later experiences could still possibly falsify it. (Hoppe, 1995, p. 29)

Empirical knowledge is hence contingent on historical facts. Neither confirmation nor falsification by observational experience can prove that a relationship between phenomena does not or does exist. By emphasizing that our knowledge of reality must stem from observational experience, they directly deny a science that avers that a priori knowledge can give us any meaningful explanation of real phenomena. However, as Hoppe and Mises point out, the statement that meaningful synthetic a priori propositions cannot exist is itself a synthetic a priori proposition. Mises has put this empiricist contradiction the following way in The Ultimate Foundation of Economic Science (1962):

The essence of logical positivism [logical empiricism] is to deny the cognitive value of a priori knowledge by pointing out that all a priori propositions are merely analytic. They do not provide new information, but are merely verbal or tautological, asserting what has already been implied in the definitions and premises. Only experience can lead to synthetic propositions. There is an obvious objection against this doctrine, viz., that this proposition that there are no synthetic a priori propositions is in itself a … synthetic a priori proposition, for it can manifestly not be established by experience. (Mises, 1962, p. 5)

Hoppe mentions a second contradiction of empiricism which regards historical events. Empiricists believe that particular events may cause any particular human action. They attempt to find such causal relationships in order to explain historical events. However, in order to do so, empiricists must assume that causality within historical sequences exists through all times. This assumption itself is not based on experiential observations, and must presuppose a priori knowledge that “time-invariantly operating causes with respect to actions exist” (Hoppe, 1995, p. 36). In addition, Hoppe identifies a third contradiction with respect to social phenomena. The empiricists believe that in order to confirm and falsify hypotheses, one must be able to learn from historical and social experience. If one would deny this, then why should one engage in empirical research at all? This however presupposes that “one admittedly cannot know at any given time what one will know at a later time and, accordingly, how one will act on the basis of this knowledge” (Hoppe, 1995, p. 37). Admitting that humans learn from historical and social experience, one cannot deny that empirical causal constants in human action do not exist. “The empiricist-minded social scientists who formulate prediction equations regarding social phenomena are simply doing nonsense” (Hoppe, 1995, p. 38). Predicting human action is not a science according to Hoppe.[1]

The empiricists are mistaken in applying the methodology of the natural sciences into the fields of social science in order to predict human actions. Unlike natural elements, human beings can and do act differently under equal conditions. Thus, social history cannot yield any knowledge that can be employed for predictive purposes. Relating this to the quantity theory of money; if the money supply for instance increases, one can still not predict whether the demand of money will change as this is entirely dependent on human action. Nonetheless, one could assert that if the demand for money stays constant and the money supply increases, then the purchasing power of money will fall (Hoppe, 1995, pp. 44-45).

(B) Historicism
Historicism, the second challenge that Mises had to face, does not take nature as its model but literary texts. Historicists believe that there are no objective laws in economics, and that “historical and economic events are whatever someone expresses or interprets them to be” (Hoppe, 1995, p. 54). Historicism is therefore extremely relativist. However, according to Hoppe also historicism is fundamentally self-contradictory. If there are only interpretations and hence no constant time-invariant relations, then there is also no historicist constant truth about history and economics. If historicism does not give us any reason to believe in its doctrine, why should we adhere to its epistemological philosophy if its proposition implies that they themselves may not be true?

Next to his refutations of empiricism and historicism, Mises had hoped that he could demonstrate the existence of true synthetic a priori propositions. Such propositions would (1) not be derived from experience, and (2) they must yield self-evident axioms so that when one tries to deny it one is involved in self-contradiction. Mises believes that these two requirements are met by the axiom of action – the proposition that human beings act and display intentional behaviour (Hoppe, 1995, pp. 60-61). According to Mises, purposeful human behaviour exhibits a person’s pursuit of an end which he attempts to reach through the employment of particular means (at least time and body). The fact that a person pursues a particular goal with his action reveals that he places a relatively higher value (preference) on the goal than any other goals of action that he could have thought of at the beginning of his action. Human action also happens sequentially, implying that the actor can only pursue one goal at a time in which he has to forego other valuable goals temporally. Action therefore also implies choices and costs. An action furthermore implies loss (and profit), because every action accompanies a certain degree of uncertainty, whether the goal achieved has resulted in the value one has expected can only be known in retrospect. All these categories of action – values, ends, means, choices, preferences, costs, profit, loss, and time – are at the heart of economics (Hoppe, 1995, pp. 61-63). This insight establishes economics as a science of human action. Or as Hoppe asserts more precisely,

all true economic theorems consist of (a) an understanding of the meaning of action, (b) a situation or situational change – assumed to be given or identified as being given – and described in terms of action-categories, and (c) a logical deduction of the consequences – again in terms of such categories – which are to result for an actor from this situation or situational change (Hoppe, 1995, pp. 63-64).

The existence of the categories of action is derived a priori from the axiom of action, and not through observation. Any attempt to disprove it is futile, since “a situation in which the categories of action would cease to have a real existence could itself never be observed or spoken of, since to make an observation and to speak are themselves actions” (Hoppe, 1995, p. 63).

My thoughts on Hoppe’s book
The book serves as an excellent summary of praxeological philosophy and is a must-read for anyone who wants to start learning more about the subject. Reading the book, one feels that it is extremely concise (around 80 pages), but also dense. Hoppe directly discusses the essential philosophical aspects that one must know in order to understand praxeology as developed by Mises, and fortunately he leaves many footnotes for further reading.

I believe that Hoppe has skillfully shown that economics is part of praxeology, and that it indisputably deals with such categories of human action as values, ends, means, choices, preferences, profit, loss, time, and causality. He has furthermore provided a well-reasoned critique of the empiricist and historicist-hermeneutical interpretations of economics by showing that they are necessarily self-contradictory.

Understanding that economics should not be conducted within the methodological framework of the natural sciences has severe implications to the ways we should deal with data of real world phenomena. If, like praxeologists claim, we cannot predict human action then there is also little reason to believe that effective social engineering is possible. The fundamentals of the praxeological methodology are therefore also immediately relevant within discussions on the roles of the state in planning the economy.

Footnotes
[1] Hoppe calls it entrepreneurship.

Bibliography
Friedman, M. & Schwartz, A.J. (1963). A Monetary History of the United States 1867-1960. Princeton: Princeton University Press.
Hoppe, H.H. (1995). Economic Science and the Austrian Method. Auburn: Ludwig von Mises Institute.
Kant, I. (1781). Critique of Pure Reason. (W.S. Pluhar, Trans.) Indianapolis: Hackett Publishing Company, Inc.
Mises von, L. (1942). Social Science and Natural Science. In R.M. Ebeling (Ed.) Money, Methods, and the Market Process (pp. 3-15). Retrieved from http://mises.org
Mises von, L. (1966). The Ultimate Foundation of Economic Science. Retrieved fromhttp://mises.org
Stolyarov II, G. (2007). The Compatibility of Hoppe’s and Rothbard’s Views of the Action Axiom. The Quarterly Journal of Austrian Economics, 10, 2, pp. 45-62.