There are two main branches of the sciences of human action: praxeology and history. History is the collection and systematic arrangement of all thedata of experience concerning human action. It deals with the con-crete content of human action. It studies all human endeavors in their infinite multiplicity and variety and all individual actions with all their accidental, special, and particular implications. It scrutinizes the ideas guiding acting men and the outcome of the actions performed. It embraces every aspect of human activities. It is on the one hand general history and on the other hand the history of various narrower fields. There is the history of political and military action, of ideas and philosophy, of economic activities, of technology, of literature, art, and science, of religion, of mores and customs, and of many other realms of human life. There is ethnology and anthropology, as far as they are not a part of biology, and there is psychology as far as it is neither physiology nor epistemology nor philosophy. There is linguistics as far as it is neither logic nor the physiology of speech .
The subject matter of all historical sciences is the past. They cannot teach us anything which would be valid for all human actions, that is, for the future too. The study of history makes a man wise [p. 31] and judicious. But it does not by itself provide any knowledge and skill which could be utilized for handling concrete tasks.
The natural sciences too deal with past events. Every experience is an experience of something passed away; there is no experience of future happenings. But the experience to which the natural sciences owe all their success is the experience of the experiment in which the individual elements of change can be observed in isolation. The facts amassed in this way can be used for induction, a peculiar procedure of inference which has given pragmatic evidence of its expediency, although its satisfactory epistemological characterization is still an unsolved problem.
The experience with which the sciences of human action have to deal is always an experience of complex phenomena. No laboratory experiments can be performed with regard to human action. We are never in a position to observe the change in one element only, all other conditions of the event remaining unchanged. Historical experience as an experience of complex phenomena does not provide us with facts in the sense in which the natural sciences employ this term to signify isolated events tested in experiments. The information conveyed by historical experience cannot be used as building material for the construction of theories and the prediction of future events. Every historical experience is open to various interpretations, and is in fact interpreted in different ways.
The postulates of positivism and kindred schools of metaphysics are therefore illusory. It is impossible to reform the sciences of human action according to the pattern of physics and the other natural sciences. There is no means to establish an a posteriori theory of human conduct and social events. History can neither prove nor disprove any general statement in the manner in which the natural sciences accept or reject a hypothesis on the ground of laboratory experiments. Neither experimental verification nor experimental falsification of a general proposition is possible in its field.
Complex phenomena in the production of which various causal chains are interlaced cannot test any theory. Such phenomena, on the contrary, become intelligible only through an interpretation in terms of theories previously developed from other sources. In the case of natural phenomena the interpretation of an event must not be at variance with the theories satisfactorily verified by experiments. In the case of historical events there is no such restriction. Commentators would be free to resort to quite arbitrary explanations. Where there is something to explain, the human mind has never been at a loss to [p. 32] invent ad hoc some imaginary theories, lacking any logical justification.
In the field of human history a limitation similar to that which the experimentally tested theories enjoin upon the attempts to interpret and elucidate individual physical, chemical, and physiological events is provided by praxeology. Praxeology is a theoretical and systematic, not a historical, science. Its scope is human action as such, irrespective of all environmental, accidental, and individual circumstances of the concrete acts. Its cognition is purely formal and general without reference to the material content and the particular features of the actual case. It aims at knowledge valid for all instances in which the conditions exactly correspond to those implied in its assumptions and inferences. Its statements and propositions are not derived from experience. They are, like those of logic and mathematics, a priori. They are not subject to verification or falsification on the ground of experience and facts. They are both logically and temporally antecedent to any comprehension of historical facts. They are a necessary requirement of any intellectual grasp of historical events. Without them we should not be able to see in the course of events anything else than kaleidoscopic change and chaotic muddle.
 Economic history, descriptive economics, and economic statistics are, of course, history.
The term sociology is used in two different meanings. Descriptive sociology deals with those historical
phenomena of human action which are not viewed in descriptive economics; it overlaps to some extent the field
claimed by ethnology and anthropology. General sociology, on the other hand, approaches historical
experience from a more nearly universal point of view than that of the other branches of history.
History proper, for instance, deals with people or with a certain geographical area. Max Weber in his
main treatise (Wirtschaft und Gesellschaft [Tübingen, 1922], pp. 513-600) deals with the town in general, i.e.,
with the whole historical experience concerning towns without any limitation to historical
periods, geographical areas, or individual peoples, nations, races, and civilizations.