The old subjectivist economists did not deny that there were outcomes of interaction that were beyond the control of any particular actor. But they did not believe that the causes of these outcomes could be determined in the same way as the causes of an outcome of the forces of nature. As they saw it economic interaction is an outcome of the choices of the separate economic actors. To understand a particular outcome, it is necessary to understand the choices of each of the individuals, or subjects, who contribute to that outcome. Hence, the economist's attempt to understand should be conducted from a subjectivist stance.
Some old subjectivists emphasize the value neutrality of subjectivism.
The old subjectivism limits the freedom of the economist to use his own value judgments. Mises discovered the new subjectivism by trying to understand the method of the old subjectivists. A deeper examination shows that, by rejecting the classical notion of natural law, they were studying a class of phenomena that was fundamentally different from that of the natural sciences. We can call this class distinctly human action . We use this term to distinguish this class from other characteristics of human beings and non-humans.