Feasibility Test of discovering moral judgment based on the foundation of reason in the view of usulians

Determining the source of moral judgment is one of the main concerns of moral philosophers. Some western thinkers have considered the collective agreement as the standard of value and basis for establishing moral rules. In Islamic thought, Usulists have used the rule of reason through jurisprudential inferences. In view of these apparent relationships, the present research tries to measure the feasibility of establishing or discovering moral judgment based on the foundation of reason in the view of Usulians, using a descriptive-analytical method. If the intrinsic validity is accepted and it is not possible to reject the rational foundations, it is possible to obtain a basis for discovering the moral judgment based on the rational foundations. However, the findings of the research show that the arguments of the defenders of the intrinsic validity of rational constructs, including their rationality, have a fundamental flaw and are ineffective in inferring moral judgment. The study shows that the use of rationality in the discovery of moral rules faces other theoretical and methodological difficulties. Differentiating the nature of authenticity and validity in rational constructions compared to moral values, the ontological distinction of value in relation to rational constructions, and criterain of values versus the rationality and rationality of rational constructions are among these difficulties.