The mean has mostly been considered in the history of Aristotelian Ethics’ commentaries as the main idea of his ethical thought so that it transformed from an ethical concept to his ethical theory. Thus, the validity of the Aristotelian ethical attitude is evaluated by the mean as the central thesis. However, it becomes apparent by pursuing the procedure of the Aristotelian investigation in the text of the Nicomachean Ethics that the mean is first presented as a possibility for the necessity (...) of the best choice’s understanding in every given practical situation. The final signification and the substantial content of the mean is that the best choice must be chosen by every individual agent at any particular action considering all the multiple, variable and conditioned factors. Because the mean is an individual intuitive grasping, it needs a right rule; relying on which, as a universal criterion, we determine any particular mean in every special circumstance. The right rule itself consists of the right reason. Having surveyed various kinds of knowledge, Aristotle arrives at practical reason, which is an agent’s dispositional power generally and in comprehending and actualizing the best particular option particularly. The mean, therefore, depends on the right rule which itself relies on the correct reason or practical understanding. (shrink)