But the experience with which the sciences of human action have to deal is essentially different. It is historical experience. It is an experience of complex phenomena, of the joint effects brought about by the co-operation of a multiplicity of elements. The social sciences are never in a position to control the conditions of change and to isolate them from one another in the way in which the experimenter proceeds in arranging his experiments. They never enjoy the advantage of observing the consequences of a change in one element only, other conditions being equal. They are never faced with facts in the sense in which the natural sciences employ this term. Every fact and every experience with which the social sciences have to deal is open to various interpretations. Historical facts and historical experience can never prove or disprove a statement in the way in which an experiment proves or disproves.
Historical experience never comments upon itself. It needs to be interpreted from the point of view of theories constructed without the aid of experimental observations. There is no need to enter into an epistemological analysis of the logical and philosophical problems involved. It is enough to refer to the fact that nobody—whether scientist or layman--ever proceeds otherwise when dealing with historical experience. Every discussion of the relevance and meaning of historical facts falls back very soon on a discussion of abstract general principles, logically antecedent to the facts to be elucidated and interpreted. Reference to historical experience can never solve any problem or answer any question. The same historical events and the same statistical figures are claimed as confirmations of contradictory theories."
From Planned Chaos, Ludwig von Mises
Pic - Queen Anne's Lace fractal (?) found here