From procedural to complex rationality relations: Observed system and observing system

Procedural rationality and substantive rationality call for two different approaches in terms of methodology and epistemology. While in the first case, the question of interest is "what is it made of?" The appropriate methodology is analytic and the epistemology, positivist. In the second case, the question will be "what does it make, and why?" the methodology complex and the epistemology, constructivist. The object of study will be different in both cases. The choice of a methodology also reflects a different view of uncertainty. As a consequence, it is impossible to use simultaneously the two rationality concepts and to study the behavior of an economic agent. How can we then classify the economical theories according to either one of the rationality concept and reasoning approach (complex or analytic)? The Economics of Convention School, developed in France, offers a conceptual framework consistent with a complex approach. It still has to adhere to that complex approach in a more total way, by assuming the economist observer's projects and aims.