Fuzzy Logic and Practical Mentally_ posited (i’tibari) Sciences in Moral Propositions

The nature of moral propositions from the point of view of Allameh Tabatabai and the validity of the "goodness and badness" that underlie them suggest that one cannot evaluate and deduce moral propositions by using either classical logic or even mathematical multi_valued logic. The philosopher proficient in jurisprudence believes in absoluteness in moral concepts and relativity in moral considerations. Moral propositions are constructional and follow the continuous variable of public interest and corruption. "Fuzzy Logic" or "The logic of ambiguity" provides a model of approximate arguments in human evaluations and can replace linguistic variables with numerical variables, concepts, variables, and many approximate and ambiguous systems and simulate in mathematical language. “Truth” is a linguistic variable because its values are linguistics such as true, very true, fairly true, not very true, untrue, not very true and not very untrue, etc. In this paper, based on the parametric representation of linguistic truth-values it is proved that so far, fuzzy logic has been the most perfect recognized reference in moral propositions for the purpose of achieving accurate evaluations of complex human decisions.