All the elements of the theoretical sciences of human action are already implied in the category of action and have to be made explicit by expounding its contents. As among these elements of teleology is also the category of causality, the category of action is the fundamental category of epistemology, the starting point of any epistemological analysis.

The very category or concept of action comprehends the concepts of means and ends, of preferring and putting aside, viz., of valuing, of success and failure, of profit and loss, of costs. As no action could be devised and ventured upon without definite ideas about the relation of cause and effect, teleology presupposes causality.

Animals are forced to adjust themselves to the natural conditions of their environment; if they do not succeed in this process of adjustment, they are wiped out. Man is the only animal that is able—within definite limits—to adjust his environment purposively to suit him better.

We can think of the evolutionary process that transformed the nonhuman ancestors of mankind into human beings as a succession of small, gradual changes spread over millions of years. But we cannot think of a mind in which the category of action would have been present only in an incomplete form, There is nothing in between a being driven exclusively by instincts and physiological impulses and a being that chooses ends and the means for the attainment of these ends. We cannot think of an acting being that would not in concreto distinguish what is end and what is means, what is success and what is failure, what he likes more and what he likes less, what is his profit or his loss derived from the action and what his costs are. In grasping all these things, he may, of course, err in his judgments concerning the role various external events and materials play in the structure of his action.

A definite mode of behavior is an action only if these distinctions are

On the earth man occupies a peculiar position that distinguishes him from and elevates him above all other entities constituting our planet. While all the other things, animate or inanimate, behave according to regular patterns, man alone seems to enjoy—within definite limits—a modicum of freedom. Man meditates about the conditions of his own self and of his environment, devises states of affairs that, as he believes, would suit him better than the existing states, and aims by purposive conduct at the substitution of a more desired state for a less desired that would prevail if he were not to interfere.

There is within the infinite expanse of what is called the universe or nature a small field in which man’s conscious conduct can influence the course of events.

It is this fact that induces man to distinguish between an external world subject to inexorable and inextricable necessity and his human faculty of thinking, cognizing, and acting. Mind or reason is contrasted with matter, the will with self-acting impulses, instincts, and physiological processes. Fully aware of the fact that his own body is subject to the same forces that determine all other things and beings, man imputes his ability to think, to will and to act to an invisible and intangible factor he calls his mind.

There were in the early history of mankind attempts to ascribe such a faculty of thinking and purposively aiming at ends chosen to many or even to all nonhuman things. Later people discovered that it was vain to deal with nonhuman things as if they were endowed with something analogous to the human mind. Then the opposite tendency developed. People tried to reduce mental phenomena to the operation of factors that were not specifically human. The most radical expression of this doctrine was already implied in the famous dictum of John Locke according to which the mind is a sheet of white paper upon which the external world writes its own story.

A new epistemology of rationalism aimed at the refutation of this integral empiricism. Leibniz added to the doctrine that nothing is in the intellect that has not previously been in the senses the proviso: except the intellect itself. Kant, awakened by Hume from his “dogmatic slumbers,” put the rationalistic doctrine upon a new basis. Experience, he taught, provides only the raw material out of which the mind forms what is called knowledge. All knowledge is conditioned by the categories that precede any data of experience both in time and in logic. The categories are a priori; they are the mental equipment of the individual that enables him to think and—we may add—to act. As all reasoning presupposes the a priori categories, it is vain to embark upon attempts to prove or to disprove them.

The empiricist reaction against apriorism centers around a misleading interpretation of the non-Euclidean geometries, the nineteenth century’s most important contribution to mathematics. It stresses the arbitrary character of axioms and premises and the tautological character of deductive reasoning. Deduction, it teaches, cannot add anything to our knowledge of reality. It merely makes explicit what was already implicit in the premises. As these premises are merely products of the mind and not derived from experience, what is deduced from them cannot assert anything about the state of the universe. What logic, mathematics, and other aprioristic deductive theories bring forward are at best convenient or handy tools for scientific operations. It is one of the tasks incumbent upon the scientist to choose for his work out of the multiplicity of the various existing systems of logic, geometry, and algebra the system that is most convenient for his specific purpose.1 The axioms from which a deductive system departs are arbitrarily selected. They do not tell us anything about reality. There is no such thing as first principles a priori given to the human mind.2 Such is the doctrine of the famous “Vienna Circle” and of other contemporary schools of radical empiricism and logical positivism.

In order to examine this philosophy, let us refer to the conflict between the Euclidian geometry and the non-Euclidian geometries which gave rise to these controversies. It is an undeniable fact that technological planning guided by the Euclidian system resulted in effects that had to be expected according to the inferences derived from this system. The buildings do not collapse, and the machines run in the expected way. The practical engineer cannot deny that this geometry aided him in his endeavors to divert events of the real external world from the course they would have taken in the absence of his intervention and to direct them towards goals that he wanted to attain. He must conclude that this geometry, although based upon definite a priori ideas, affirms something about reality and nature. The pragmatist cannot help admitting that Euclidian geometry works in the same way in which all a posteriori knowledge provided by the experimental natural sciences works. Aside from the fact that the arrangement of laboratory experiments already presupposes and implies the validity of the Euclidian scheme, we must not forget that the fact that the George Washington bridge over the Hudson River and many thousand other bridges tender the services the constructors wanted to get confirms the practical truth not only of the applied teachings of physics, chemistry, and metallurgy, but no less of those of the geometry of Euclid. This means that the axioms from which Euclid starts tell us something about the external world that to our mind must appear no less “true” than the teachings of the experimental natural sciences.

The critics of apriorism refer to the fact that for the treatment Of certain problems recourse to one of the non-Euclidian geometries appears more convenient than recourse to the Euclidian system. The solid bodies and light rays of our environment, says Reichenbach, behave according to the laws of Euclid. But this, he adds, is merely “a fortunate empirical fact.” Beyond the space of our environment the physical world behaves according to other geometries.3 There is no need to argue this point. For these other geometries also start from a priori axioms, not from experimental facts. What the panempiricists fail to explain is how a deductive theory, starting from allegedly arbitrary postulates, renders valuable, even indispensable, services in the endeavors to describe correctly the conditions of the external world and to deal with them successfully.

The fortunate empirical fact to which Reichenbach refers is the fact that the human mind has the ability to develop theories which, although a priori, are instrumental in the endeavors to construct any a posteriori system of knowledge. Although logic, mathematics, and praxeology are not derived from experience, they are not arbitrarily made, but imposed upon us by the world in which we live and act and which we want to study.4  They are not empty, not meaningless, and not merely verbal. They are—for man—the most general laws of the universe, and without them no knowledge would be accessible to man.

The a priori categories are the endowment that enables man to attain all that is specifically human and distinguishes him from all other beings. Their analysis is analysis of the human condition, the role man plays in the universe. They are the force that enables man to create and to produce all that is called human civilization.

• 1Cf. Louis Rougier, Traité de la connaissance (Paris, 1955), pp. 13 ff.
• 2Ibid., pp. 47 ff.
• 3Cf. Hans Reichenbach, The Rise of Scientific Philosophy (University of California Press, 1951), p. 137.
• 4Cf. Morris Cohen, A Preface to Logic (New York: Henry Holt & Co., 1944), pp. 44 and 92; Mises, Human Action , pp. 72-91.

The concepts of natural selection and evolution make it possible to develop a hypothesis about the emergence of the logical structure of the human mind and the a priori.

Animals are driven by impulses and instincts. Natural selection eliminated those specimens and species which developed instincts that were a liability in the struggle for survival. Only those endowed with impulses serviceable to their preservation survived and could propagate their species.

We are not prevented from assuming that in the long way that led from the nonhuman ancestors of man to the emergence of the species Homo sapiens some groups of advanced anthropoids experimented, as it were, with categorial concepts different from those of Homo sapiens and tried to use them for the guidance of their conduct. But as such pseudo categories were not adjusted to the conditions of reality, behavior directed by a quasi reasoning based upon them was bound to fail and to spell disaster to those committed to it. Only those groups could survive whose members acted in accordance with the right categories, i.e., with those that were in conformity with reality and therefore—to use the concept of pragmatism—worked.5

However, reference to this interpretation of the origin of the a priori categories does not entitle us to call them a precipitate of experience, of a prehuman and prelogical experience as it were.6 We must not blot out the fundamental difference between finality and the absence of finality.

The Darwinian concept of natural selection tries to explain phylogenetic change without recourse to finality as a natural phenomenon. Natural selection is operative not only without any purposive interference on the part of external elements; it operates also without any intentional behavior on the part of the various specimens concerned.

Experience is a mental act on the part of thinking and acting men. It is impossible to assign to it any role in a purely natural chain of causation the characteristic mark of which is the absence of intentional behavior. It is logically impossible to compromise between design and the absence of design. Those primates who had the serviceable categories survived, not because, having had the experience that their categories were serviceable, they decided to cling to them. They survived because they did not resort to other categories that would have resulted in their own extirpation. In the same way in which the evolutionary process eliminated all other groups whose individuals, because of specific properties of their bodies, were not fit for life under the special conditions of their environment, it eliminated also those groups whose minds developed in a way that made their use for the guidance of conduct pernicious.

The a priori categories are not innate ideas. What the normal—healthy—child inherits from his parents are not any categories, ideas, or concepts, but the human mind that has the capacity to learn and to conceive ideas, the capacity to make its bearer behave as a human being, i.e., to act.

However we may think about this problem, one thing is certain. Since the a priori categories emanating from the logical structure of the human mind have enabled man to develop theories the practical application of which has aided him in his endeavors to hold his own in the struggle for survival and to attain various ends that he wanted to attain, these categories provide some information about the reality of the universe. They are not merely arbitrary assumptions without any informative value, not mere conventions that could as well be replaced by some other conventions. They are the necessary mental tool to arrange sense data in a systematic way, to transform them into facts of experience, then these facts into bricks to build theories, and finally the theories into technics to attain ends aimed at.

The animals too are equipped with senses; some of them are even capable of sensing stimuli that do not affect man’s senses. What prevents them from taking advantage of what their senses convey to them in the way man does, is not an inferiority of their sense equipment, but the fact that they lack what is called the human mind with its logical structure, its a priori categories.

Theory as distinct from history is the search for constant relations between entities or, what means the same, for regularity in the succession of events. In establishing epistemology as a theory of knowledge, the philosopher implicitly assumes or asserts that there is in the intellectual effort of man something that remains unchanged, viz., the logical structure of the human mind.

If there were nothing permanent in the manifestations of the human mind, there could not be any theory of knowledge, but merely a historical account of the various attempts made by men to acquire knowledge. The condition of epistemology would resemble that of the various branches of history, e.g., what is called political science. In the same way in which political science merely records what has been done or has been suggested in its field in the past, but is at a loss to tell anything about invariant relations among the elements with which it deals, epistemology would have to restrict its work to the assemblage of historical data about the mental activities of the past.

In stressing the fact that the logical structure of the human mind is common to all specimens of the species Homo sapiens, we do not want to assert that this human mind as we know it is the only or the best possible mental tool that could be devised or that has ever been and will ever be called into existence. In epistemology, as well as in all other sciences, we are dealing neither with eternity nor with conditions in parts of the universe from which no sign reaches our orbit nor with what may possibly happen in future aeons. Perhaps there are somewhere in the infinite universe beings whose minds outrank our minds to the same extent as our minds surpass those of the insects. Perhaps there will once somewhere live beings who will look upon us with the same condescension as we look upon amoebae. But scientific thinking cannot indulge in such imagery. It is bound to limit itself to what is accessible to the human mind as it is.

• 5Mises, Human Action, pp. 86 ff.
• 6As J. Benda, La crise du rationalisme (Paris, 1949), pp. 27 ff., suggests.

One does not annul the cognitive significance of the a priori by qualifying it as tautological. A tautology must ex definitione be the tautology—restatement—of something said already previously. If we qualify Euclidian geometry as a hierarchical system of tautologies, we may say: The theorem of Pythagoras is tautological as it expresses merely something that is already implied in the definition of a right-angled triangle.

But the question is: How did we get the first—the basic—proposition of which the second—the derived—proposition is merely a tautology? In the case of the various geometries the answers given today are either (a) by an arbitrary choice or (b) on account of its convenience or suitability. Such an answer cannot be given with regard to the category of action.

Neither can we interpret our concept of action as a precipitate of experience. It makes sense to speak of experience in cases in which also something different from what was experienced in concreto could have possibly been expected before the experience. Experience tells us something we did not know before and could not learn but for having had the experience. But the characteristic feature of a priori knowledge is that we cannot think of the truth of its negation or of something that would be at variance with it. What the a priori expresses is necessarily implied in every proposition concerning the issue in question. It is implied in all our thinking and acting.

If we qualify a concept or a proposition as a priori, we want to say: first, that the negation of what it asserts is unthinkable for the human mind and appears to it as nonsense; secondly, that this a priori concept or proposition is necessarily implied in our mental approach to all the problems concerned, i.e., in our thinking and acting concerning these problems.

The a priori categories are the mental equipment by dint of which man is able to think and to experience and thus to acquire knowledge. Their truth or validity cannot be proved or refuted as can those of a posteriori propositions, because they are precisely the instrument that enables us to distinguish what is true or valid from what is not.

What we know is what the nature or structure of our senses and of our mind makes comprehensible to us. We see reality, not as it “is” and may appear to a perfect being, but only as the quality of our mind and of our senses enables us to see it. Radical empiricism and positivism do not want to admit this. As they describe it, reality writes, as experience, its own story upon the white sheets of the human mind. They admit that our senses are imperfect and do not fully and faithfully reflect reality. But they do not examine the power of the mind to produce, out of the material provided by sensation, an undistorted representation of reality. In dealing with the a priori we are dealing with the mental tools that enable us to experience, to learn, to know, and to act. We are dealing with the mind’s power, and this implies that we are dealing with the limits of its power.

We must never forget that our representation of the reality of the universe is conditioned by the structure of our mind as well as of our senses. We cannot preclude the hypothesis that there are features of reality that are hidden to our mental faculties but could be noticed by beings equipped with a more efficient mind and certainly by a perfect being. We must try to become aware of the characteristic features and limitations of our mind in order not to fall prey to the illusion of omniscience.

The positivistic conceit of some of the forerunners of modem positivism manifested itself most blatantly in the dictum: God is a mathematician. How can mortals, equipped with manifestly imperfect senses, claim for their mind the faculty of conceiving the universe in the same way in which the wholly perfect may conceive it? Man cannot analyze essential features of reality without the help provided by the tools of mathematics. But the perfect being?

After all, it is quite supererogatory to waste time upon controversies concerning the a priori. Nobody denies or could deny that no human reasoning and no human search for knowledge could dispense with what these a priori concepts, categories, and propositions tell us. No quibbling can in the least affect the fundamental role played by the category of action for all the problems of the science of man, for praxeology, for economics, and for history.

No thinking and no acting would be possible to man if the universe were chaotic, i.e., if there were no regularity whatever in the succession and concatenation of events. In such a world of unlimited contingency nothing could be perceived but ceaseless kaleidoscopic change. There would be no possibility for man to expect anything. All experience would be merely historical, the record of what has happened in the past. No inference from past events to what might happen in the future would be permissible. Therefore man could not act. He could at best be a passive spectator and would not be able to make any arrangements for the future, be it only for the future of the impending instant. The first and basic achievement of thinking is the awareness of constant relations among the external phenomena that affect our senses. A bundle of events that are regularly related in a definite way to other events is called a specific thing and as such distinguished from other specific things. The starting point of experimental knowledge is the cognition that an A is uniformly followed by a B. The utilization of this knowledge either for the production of B or for the avoidance of the emergence of B is called action. The primary objective of action is either to bring about B or to prevent its happening.

Whatever philosophers may say about causality, the fact remains that no action could be performed by men not guided by it. Neither can we imagine a mind not aware of the nexus of cause and effect. In this sense we may speak of causality as a category or an a priori of thinking and acting.

To the man anxious to remove by purposive conduct some uneasiness felt, the question occurs: Where, how, and when would it be necessary to interfere in order to obtain a definite result? Cognizance of the relation between a cause and its effect is the first step toward man’s orientation in the world and is the intellectual condition of any successful activity. All attempts to find a satisfactory logical, epistemological, or metaphysical foundation for the category of causality were doomed to fail. All we can say about causality is that it is a priori not only of human thought but also of human action.

Eminent philosophers have tried to elaborate a complete list of the a priori categories, the necessary conditions of experience and thought. One does not belittle these attempts at analysis and systematization if one realizes that any proposed solution leaves a broad margin for the individual thinker’s discretion. There is only one point about which there cannot be any disagreement, viz., that they all can be reduced to the a priori insight into the regularity in the succession of all observable phenomena of the external world. In a universe lacking this regularity there could not be any thinking and nothing could be experienced. For experience is the awareness of identity or the absence of identity in what is perceived; it is the first step toward a classification of events. And the concept of classes would be empty and useless if there were no regularity.

If there were no regularity, it would be impossible to resort to classification and to construct a language. All words signify bundles of regularly connected acts of perception or regular relations among such bundles. This is valid also of the language of physics, which the positivists want to elevate to the rank of a universal language of science. In a world without regularity there would not be any possibility of formulating “protocol sentences.”7  But even if it could be done, such a “protocol language” could not be the starting point of a science of physics. It would merely express historical facts.

If there were no regularity, nothing could be learned from experience. In proclaiming experience as the main instrument of acquiring knowledge, empiricism implicitly acknowledges the principles of regularity and causality. When the empiricist refers to experience, the meaning is: as A was in the past followed by B, and as we assume that there prevails a regularity in the concatenation and succession of natural events, we expect that A will also in the future be followed by B. Therefore there is a fundamental difference between the meaning of experience in the field of natural events and in the field of human action.

• 7About the “protocol language,” cf. Carnap, “Die physikalische Sprache als Universalsprache der Wissenschaft,” Erkenntnis, II (1931), 432-65, and Carnap, “Uber Protokollsätze,” Erkenntnis, III (1932/33), 215-28.

Reasoning is necessarily always deductive. This was implicitly admitted by all the attempts to justify ampliative induction by demonstrating or proving its logical legitimacy, i.e., by providing a deductive interpretation of induction. The plight of empiricism consists precisely in its failure to explain satisfactorily how it is possible to infer from observed facts something concerning facts yet unobserved.

All human knowledge concerning the universe presupposes and rests upon the cognition of the regularity in the succession and concatenation of observable events. It would be vain to search for a rule if there were no regularity. Inductive inference is conclusion from premises that invariably include the fundamental proposition of regularity.

The practical problem of ampliative induction must be clearly distinguished from its logical problem. For the men who embark upon inductive inference are faced with the problem of correct sampling. Did we or did we not, out of the innumerable characteristics of the individual case or cases observed, choose those which are relevant for the production of the effect in question? Serious shortcomings of endeavors to learn something about the state of reality, whether in the mundane search for truth in everyday life or in systematic scientific research, are due to mistakes in this choice. No scientist doubts that what is correctly observed in one case must also be observed in all other cases offering the same conditions. The aim of laboratory experiments is to observe the effects of a change in one factor only, all the other factors remaining unchanged. Success or failure of such experiments presupposes, of course, the control of all the conditions that enter into their arrangement. The conclusions derived from experimentation are not based upon the repetition of the same arrangement, but upon the assumption that what happened in one case must necessarily also happen in all other cases of the same type. It would be impossible to infer anything from one case or from an innumerable series of cases without this assumption, which implies the a priori category of regularity. Experience is always the experience of past events and could not teach us anything about future events if the category of regularity were merely a vain assumption.

The panphysicalists’ probability approach to the problem of induction is an abortive attempt to deal with induction without reference to the category of regularity. If we do not take account of regularity, there is no reason whatever to infer from anything that happened in the past what will happen in the future. As soon as we try to dispense with the category of regularity, all scientific effort appears useless, and the search for knowledge about what is popularly called the laws of nature becomes meaningless and futile. What is natural science about if not about the regularity in the flux of events?

Yet the category of regularity is rejected by the champions of logical positivism. They pretend that modern physics has led to results incompatible with the doctrine of a universally prevailing regularity and has shown that what has been considered by the “school philosophy” as the manifestation of a necessary and inexorable regularity is merely the product of a great number of atomic occurrences. In the microscopic sphere there is, they say, no regularity whatever. What macroscopic physics used to consider as the outcome of the operation of a strict regularity is merely the result of a great number of purely accidental elementary processes. The laws of macroscopic physics are not strict laws, but actually statistical laws. It could happen that the events in the microscopic sphere produce in the macroscopic sphere events that are different from those described by the merely statistical laws of macroscopic physics, although, they admit, the probability of such an occurrence is very small. But, they contend, the cognition of this possibility demolishes the idea that there prevails in the universe a strict regularity in the succession and concatenation of all events. The categories of regularity and causality must be abandoned and replaced by the laws of probability.8

It is true that the physicists of our age are faced with behavior on the part of some entities that they cannot describe as the outcome of a discernible regularity. However, this is not the first time that science has been faced with such a problem. The human search for knowledge must always encounter something that it cannot trace back to something else of which it would appear as the necessary effect. There is always in science some ultimate given. For contemporary physics the behavior of the atoms appears as such an ultimate given. The physicists are today at a loss to reduce certain atomic processes to their causes. One does not detract from the marvelous achievements of physics by establishing the fact that this state of affairs is what is commonly called ignorance.

What makes it possible for the human mind to orient itself in the bewildering multiplicity of external stimuli that affect our senses, to acquire what is called knowledge, and to develop the natural sciences is the cognition of an inevitable regularity and uniformity prevailing in the succession and concatenation of such events. The criterion that induces us to distinguish various classes of things is the behavior of these things. If a thing in only one regard behaves (reacts to a definite stimulus) in a way different from the behavior of other things to which it is equal in all other respects, it must be assigned to a different class.

We may look upon the molecules and the atoms the behavior of which is at the bottom of the probabilistic doctrines either as original elements or as derivatives of the original elements of reality. It does not matter which of these alternatives we choose. For in any case their behavior is the outcome of their very nature. (To say it more correctly: It is their behavior that constitutes what we call their nature) As we see it, there are different classes of these molecules and atoms. They are not uniform; what we call molecules and atoms are groups composed of various subgroups the members of each of which in some regards differ in their behavior from the members of the other subgroups. If the behavior of the members of the various subgroups were different from what it is or if the numerical distribution of subgroup membership were different, the joint effect produced by the behavior of all the members of the groups would be different too. This effect is determined by two factors: the specific behavior of the members of each subgroup and the size of subgroup membership.

If the proponents of the probabilistic doctrine of induction had acknowledged the fact that there are various subgroups of microscopic entities, they would have realized that the joint effect of the operation of these entities results in what the macroscopic doctrine calls a law admitting of no exception. They would have had to confess that we do not know today why the subgroups differ from one another in some regards and how, out of the interaction of the members of the various subgroups, the definite joint effect emerges in the macroscopic sphere. Instead of this procedure they arbitrarily ascribe to the individual molecules and atoms the faculty of choosing among various alternatives of behavior. Their doctrine does not essentially differ from primitive animism. Just as the primitives ascribed to the “soul” of the river the power to choose between quietly flowing in its customary bed or inundating the adjacent fields, so they believe that these microscopic entities are free to determine some characteristics of their behavior, e.g., the speed and the path of their movements. In their philosophy it is implied that these microscopic entities are acting beings just like men.

But even if we were to accept this interpretation, we must not forget that human action is entirely determined by the individuals’ physiological equipment and by all the ideas that were working in their minds. As we do not have any reason to assume that these microscopic entities are endowed with a mind generating ideas, we must assume that what are called their choices necessarily correspond to their physical and chemical structure. The individual atom or molecule behaves in a definite environment and under definite conditions precisely as its structure enjoins it. The speed and the path of its movements and its reaction to any encounters with factors external to its own nature or structure are strictly determined by this nature or structure. If one does not accept this interpretation, one indulges in the absurd metaphysical assumption that these molecules and atoms are equipped with free will in the sense which the most radical and naive indeterminist doctrines ascribed to man.

Bertrand Russell tries to illustrate the problem by comparing the position of quantum mechanics with regard to the behavior of the atoms to that of a railroad with regard to the behavior of the people making use of its facilities. The booking-office clerk at Paddington can discover, if he chooses, what proportion of travelers from that station go to Birmingham, what proportion to Exeter, and so on, but he knows nothing of the individual reasons that lead to one choice in one case and another in another. But Russell has to admit that the cases are not “wholly analogous“ because the clerk can in his nonprofessional moments find out things about human beings that they do not mention when they are taking tickets, while the physicist in observing atoms has no such advantage.9

It is characteristic of the reasoning of Russell that he exemplifies his case by referring to the mind of a subaltern clerk to whom the unvarying performance of a strictly limited number of simple operations is assigned. What such a man (whose work could be performed as well by a vending automaton) thinks about things that transcend the narrow sphere of his duties is without avail. To the promoters who took the initiative in advancing the project of the railroad, to the capitalists who invested in the company, and to the managers who administer its operations, the problems involved appear in a quite different light. They built and operate the road because they anticipate the fact that there are certain reasons that will induce a number of people to travel from one point of their route to another. They know the conditions that determine these people’s behavior, they know also that these conditions are changing, and they are intent upon influencing the size and the direction of these changes in order to preserve and to increase their patronage and the enterprise’s proceeds. Their conduct of business has nothing to do with a reliance upon the existence of a mythical “statistical law.” It is guided by the insight that there is a latent demand for travel facilities on the part of such a number of people that it pays to satisfy it by the operation of a railroad. And they are fully aware of the fact that the quantity of service they are able to sell could be drastically reduced one day to such an extent that they would be forced to go out of business.

Bertrand Russell and all other positivists referring to what they call “statistical laws” are committing a serious blunder in commenting upon human statistics, i.e., statistics dealing with facts of human action as distinguished from the facts of human physiology. They do not take into account the fact that all these statistical figures are continually changing, sometimes more, sometimes less rapidly. There is in human valuations and consequently in human actions no such regularity as in the field investigated by the natural sciences. Human behavior is guided by motives, and the historian dealing with the past as well as the businessman intent upon anticipating the future must try to “understand” this behavior.10

If the historians and the acting individuals were not able to apply this specific understanding of their fellow men’s behavior, and if the natural sciences and the acting individuals were not in a position to grasp something about the regularity in the concatenation and succession of natural events, the universe would appear to them as an unintelligible chaos and they could not contrive any means for the attainment of any ends. There would not be any reasoning, any knowledge, or any science, and there would not be any purposive influencing of environmental conditions on the part of man.

The natural sciences are possible only because there prevails regularity in the succession of external events. Of course, there are limits to what man can learn about the structure of the universe. There are unobservables and there are relations about which science up to now has not provided an interpretation. But the awareness of these facts does not falsify the categories of regularity and causality.

• 8Cf. Reichenbach, op. cit., pp. 157 ff.
• 9B. Russell, Religion and Science (London: Home University Library, 1936), pp. 152 ff.
• 10About the “understanding,” see below pp. 48 ff.

Empiricism proclaims that experience is the only source of human knowledge and rejects as a metaphysical prepossession the idea that all experience presupposes a priori categories. But starting from its empiricistic approach, it postulates the possibility of events that have never been experienced by any man. Thus, we are told, physics cannot exclude the possibility that “when you put an ice cube into a glass of water, the water starts boiling and the ice cube gets as cold as the interior of a deep-freezing cabinet.”11

However, this neoempiricism is far from being consistent in the application of its doctrine. If there is no regularity in nature, nothing justifies the distinction between various classes of things and events. If one calls some molecules oxygen and others nitrogen, one implies that each member of these classes behaves in a definite way different from the behavior of the members of other classes. If one assumes that the behavior of an individual molecule can deviate from the way in which other molecules behave, one must either assign it to a special class or one must assume that its deviation was induced by the intervention of something to which other members of its class had not been exposed. If one says that one cannot exclude the possibility “that some day the molecules of the air in our room, by pure chance, arrive at an ordered state such that the molecules of oxygen are assembled on one side of the room and those of nitrogen on the other,”12  one implies that there is nothing either in the nature of oxygen and nitrogen or in the environment in which they are dwelling that results in the way in which they are distributed in the air. One assumes that the behavior of the individual molecules in all other regards is determined by their constitution, but that they are “free” to choose the place of their dwelling. One assumes quite arbitrarily that one of the characteristics of the molecules, viz., their movement, is not determined, while all their other characteristics are determined. One implies that there is something in the nature of the molecules—one is tempted to say: in their “soul”—that gives them the faculty of “choosing” the path of their wanderings. One fails to realize that a complete description of the behavior of the molecules ought also to include their movements. It would have to deal with the process that makes the molecules of oxygen and nitrogen associate with one another in the way in which they do in the air.

If Reichenbach had lived as a contemporary of magicians and tribal medicine men, he would have argued: Some people are afflicted with a disease having definite symptoms that kills them; others remain healthy and alive. We do not know of any factor the presence of which would cause the suffering of those stricken and the absence of which would cause the immunity of others. It is obvious that these phenomena cannot be dealt with scientifically if you cling to the superstitious concept of causality. All that we can know about them is the “statistical law” that X% of the population were afflicted and the rest not.

• 11Cf. Reichenbach, op. cit., p. 162.
• 12Ibid., p. 161.

Determinism must be clearly distinguished from materialism. Materialism declares that the only factors producing change are those that are accessible to investigation by the methods of the natural sciences. It does not necessarily deny the fact that human ideas, judgments of value, and volitions are real too and can produce definite changes. But as far as it does not deny this, it asserts that these “ideal” factors are the inevitable result of external events that necessarily beget in the bodily structure of men definite reactions. It is only a deficiency of the present state of the natural sciences that prevents us from imputing all manifestations of the human mind to the material—physical, chemical, biological and physiological—events that have brought them about. A more perfect knowledge, they say, will show how the material factors have necessarily produced in the man Mohammed the Moslem religion, in the man Descartes co-ordinate geometry, and in the man Racine Phaedra

It is useless to argue with the supporters of a doctrine that merely establishes a program without indicating how it could be put into effect. What can be done and must be done is to disclose how its harbingers contradict themselves and what consequences must result from its consistent application.

If the emergence of every idea is to be dealt with as one deals with the emergence of all other natural events, it is no longer permissible to distinguish between true and false propositions. Then the theorems of Descartes are neither better nor worse than the bungling of Peter, a dull candidate for a degree, in his examination paper. The material factors cannot err. They have produced in the man Descartes co-ordinate geometry and in the man Peter something that his teacher, not enlightened by the gospel of materialism, considers as nonsense. But what entitles this teacher to sit in judgment upon nature? Who are the materialist philosophers to condemn what the material factors have produced in the bodies of the “idealistic” philosophers.

It would be useless for the materialists to point to pragmatism’s distinction between what works and what does not work. For this distinction introduces into the chain of reasoning a factor that is foreign to the natural sciences, viz., finality. A doctrine or proposition works if conduct directed by it brings about the end aimed at. But the choice of the end is determined by ideas, is in itself a mental fact. So is also the judgment whether or not the end chosen has been attained. For consistent materialism it is not possible to distinguish between purposive action and merely vegetative, plant-like living.

Materialists think that their doctrine merely eliminates the distinction between what is morally good and morally bad. They fail to see that it no less wipes out any difference between what is true and what is untrue and thus deprives all mental acts of any meaning. If there stands between the “real things” of the external world and the mental acts nothing that could be looked upon as essentially different from the operation of the forces described by the traditional natural sciences, then we must put up with these mental phenomena in the same way as we respond to natural events. For a doctrine asserting that thoughts are in the same relation to the brain in which gall is to the liver,13  it is not more permissible to distinguish between true and untrue ideas than between true and untrue gall.

• 13Karl Vogt, Köhlerglaube und Wissenschaft (2nd ed.; Giessen, 1855), p. 32.

The insurmountable difficulties that any materialistic interpretation of reality encounters can be shown in an analysis of the most popular materialistic philosophy, Marxian dialectical materialism.

Of course, what is called dialectical materialism is not a genuine materialistic doctrine. In its context the factor that produces all changes in the ideological and social conditions of man’s history is the “material productive forces.” Neither Marx nor any of his followers defined this term. But from all the examples they provided one must infer that what they had in mind was the tools, machines, and other artifacts that men employ in their productive activities. Yet these instruments are in themselves not ultimate material things, but the products of a purposive mental process.14  But Marxism is the only attempt to carry a materialistic or quasi-materialistic doctrine beyond the mere enunciation of a metaphysical principle and to deduce from it all other manifestations of the human mind. Thus, we must refer to it if we want to show the fundamental shortcoming of materialism.

As Marx sees it, the material productive forces bring forth—independently of the will of men—the “production relations,” i.e., the social system of property laws, and their “ideological superstructure,” i.e., the juridical, political, religious, artistic, or philosophical ideas.15  In this scheme, action and volition are ascribed to the material productive forces. They want to attain a definite goal, viz., they want to be freed from fetters that are hindering their development. Men are mistaken when they believe that they themselves are thinking, resorting to judgments of value, and acting. In fact, the production relations, the necessary effect of the prevailing stage of the material productive forces, are determining their ideas, volitions, and actions. All historical changes are ultimately produced by the changes in the material productive forces, which—as Marx implicitly assumes—are independent of human influence. All human ideas are the adequate superstructure of the material productive forces. These forces aim ultimately at the establishment of socialism, a transformation that is bound to come “with the inexorability of a law of nature.”

Now let us for the sake of argument admit that the material productive forces have a constitution such that they are continually trying to free themselves from fetters upon their development. But why must, out of these attempts, first capitalism and, at a later stage of their development, socialism emerge? Do these forces reflect upon their own problems and finally reach the conclusion that the existing property relations, from having been forms of their own (viz., the forces’) development, have turned into fetters16  and that therefore they no longer correspond (”entsprechen”) to the present stage of their (viz., the forces’) development?17  And do they, on the ground of this insight, resolve that these fetters have to “burst asunder,” and do they then proceed to action that causes them to burst asunder? And do they determine what new production relations have to take the place of the burst ones?

The absurdity of ascribing such thinking and acting to the material productive forces is so blatant that Marx himself paid but little attention to his famous doctrine when later, in his main treatise, Capital, he made more specific his prognostication about the coming of socialism. Here he refers not merely to action on the part of the material productive forces. He speaks of the proletarian masses who, dissatisfied with the progressive impoverishment that capitalism allegedly brings upon them, aim at socialism, obviously because they consider it as a more satisfactory system.18

Every variety of materialistic or quasi-materialistic metaphysics must imply converting an inanimate factor into a quasi man and ascribing to it the power to think, to pass judgments of value, to choose ends, and to resort to means for the attainment of the ends chosen. It must shift the specifically human faculty of acting to a nonhuman entity that it implicitly endows with human intelligence and discernment. There is no way to eliminate from an analysis of the universe any reference to the mind. Those who try it merely substitute a phantom of their own invention for reality.

From the point of view of his professed materialism—and, for that matter, from the point of view of any materialistic doctrine—Marx did not have the right to reject as false any doctrines developed by those with whom he disagreed. His materialism would have enjoined upon him a kind of listless recognition of any opinion and a readiness to attach to every idea advanced by a human being the same value as to any other idea advanced by somebody else. To escape such a self-defeating conclusion, Marx took recourse to his scheme of philosophy of history. He pretended that, by dint of a special charisma, denied to other mortals, he had a revelation that told him what course history must necessarily and unavoidably take. History leads to socialism. The meaning of history, the purpose for which man has been created (it is not said, by whom) is to realize socialism. There is no need to pay any attention to the ideas of people whom this message did not reach or who stubbornly refuse to believe in it.

What epistemology has to learn from this state of affairs is this: Any doctrine that teaches that some “real” or “external” forces write their own story in the human mind and thus tries to reduce the human mind to an apparatus that transforms “reality” into ideas in the way in which the digestive organs assimilate food is at a loss to distinguish between what is true and what is not. The only way it can avoid a radical skepticism that does not have any means of sifting truth from falsehood in ideas is by distinguishing between “good” men, i.e., those who are equipped with the faculty of judging in conformity with the mysterious superhuman power that directs all affairs of the universe, and “bad” men, who lack this faculty. It must consider as hopeless any attempts to change the opinions of the “bad” men by discursive reasoning and persuasion. The only means to bring to an end the conflict of antagonistic ideas is to exterminate the “bad” men, i.e., the carriers of ideas that are different from those of the “good” men. Thus, materialism ultimately engenders the same methods of dealing with dissent that tyrants used always and everywhere.

In establishing this fact epistemology provides a clue for the understanding of the history of our age.

• 14Cf. Mises, Theory and History, pp. 108 ff.
• 15Cf. Karl Marx, Zur Kritik der politischen Oekonomie, ed. Kautsky (Stuttgart, 1897), pp. x-xii.
• 16Marx, op. cit., p. xi.
• 17Marx and Engels, The Communist Manifesto, I.
• 18Marx, Das Kapital (7th ed.; Hamburg, 1914), Vol. I, ch. xxiv, p. 728. For a critical analysis of this argumentation, see Mises, Theory and History, pp. 102 ff.