There is no such thing as a mere recording of unadulterated facts apart from any reference to theories. As soon as two events are recorded together or integrated into a class of events, a theory is operative. The question whether there is any connection between them can only be answered by a theory, i.e., in the case of human action by praxeology.

Economic history is possible only because there is an economic theory capable of throwing light upon economic actions. If there were no economic theory, reports concerning economic facts would be nothing more than a collection of unconnected data open to any arbitrary interpretation.

Logical thinking and real life are not two separate orbits. Logic is for man the only means to master the problems of reality. What is contradictory in theory is no less contradictory in reality.

It is a poor makeshift to dispose of a theory by referring to its historical background, to the “spirit” of its time, to the material conditions of the country of its origin, and to any per-sonal qualities of its authors. A theory is either correct or incorrect. It may happen that the present state of our knowledge does not allow a decision with regard to its correctness or incorrectness. But a theory can never be valid for a bourgeois or an American if it is invalid for a proletarian or a Chinese.