Ayatollah Mesbah Yazdi's view on the criterion of the validity of moral propositions is a different view from the general Muslim philosophers and theologians. He does not accept the common view of philosophers on the basis of moral propositions on fame (Mashhurat), and also Allameh Tabatabai's view on the basis of moral propositions on human conventional statements, and tries to show that moral propositions are rooted in facts. Ayatollah Mesbah does not accept the theologians' theory of self-evidence of good and evil, and believes that even principles such as the good of justice and the evilness of oppression need argument. He believes that the criterion of good or bad actions and the validity of moral propositions is their proportionality with the ultimate goal and true perfection of man. In this article, by descriptive method and text analysis, while explaining Ayatollah Mesbah's view on the criterion of good and evil, first an attempt is made to assess the extent to which his view to defend philosophers is consistent with the expressions of philosophers themselves.