In this text Menger continues his criticism of the German Historical School methodological tenets, arguing that there are different valid branches of economic research. A theoretical or general branch in contrast to the historical or particular, which identifies types and establishes laws. This theoretical kind of investigation is, then, divided in a realistic and an exact “orientations of research”, the former contemplating several aspects of a particular complex economic phenomenon and the latter isolating the effects of a particular cause, such as the search for economic gain, and establishing exact laws that are valid only in this abstract setting.