Revisiting Fakhr al-Rāzī’s Stance on Rational Good and Evil as the Basis for Moral Responsibility and Khwājah al-Ṭūsī’s Theological Critique

The issue of rational good and evil (husn wa qubh 'aqli) is intrinsically linked to human ethics, free will, and moral responsibility, playing a decisive role in the value judgments of human actions. Fakhr al-Razi, in his analysis of this issue, adopted a deep, systematic, and argumentative approach. By denying the obligatory implication of reason regarding the goodness and badness of actions, he believed that moral obligation and responsibility are realized solely through divine command and prohibition. Consequently, human moral responsibility is a product of religious law. Nevertheless, Fakhr al-Razi accepts a form of rational perception of good and evil on a descriptive level; a perception that, in his view, lacks obligatory (status/character) and cannot be the source of obligation or the basis for deserving praise and blame. In contrast, Imami theologians believe that humans are addressed by moral values and bear moral responsibility not only through religious law but also through reason. Khwajah Tusi argues that moral responsibility is conceivable even before the advent of religious law, as religious law is not the creator of moral values but rather the revealer and confirmator of rulings that reason has already grasped. In his view, if the goodness and badness of actions are not inherent and rational, and their determination is entirely delegated to religion, the foundation of all moral judgment and the true distinction between good and evil will collapse. This article, using an analytical-descriptive method, examines the foundations of Fakhr al-Razi’s viewpoint on rational good and evil and its role in explaining human moral responsibility, and in comparison with Khwajah Tusi’s perspective, critically analyzes it.