Abstract (Translated):
The assumption of rationality is one of the most important as well most controversial assumptions of economic science and of the theory of rational choice. But there are many difficulties associated with the concept of economic rationality, or the classical model of rationality, which is usually understood as the principle according to which people act rationally in the sense that they tend to adopt the best means which they suppose are oriented toward the satisfaction of their unquestioned goals. To understand properly the scope of such concept it is important to analyze the meaning of rationality and to distinguish between theoretical rationality and practical rationality and to consider the problem or free will and determinism as well. To understand how people make decisions that depart from the optimal model different notions of rationality are presented: instrumental rationality, substantive rationality and procedural rationality among others.