The present study comparatively examines the concept of the “stupidity of reason” (balāhat al-ʿaql) in the thought of Mulla Ṣadrā and Javadi Amoli, a relatively underexplored topic in Islamic philosophy. Mulla Ṣadrā conceives reason not merely as a tool for understanding universal concepts, but as a dimension of human existence that evolves from potentiality to actuality through the soul’s substantial motion. This view emphasizes the ontological and epistemological significance of intellect in the human journey toward perfection. Javadi interprets the stupidity of reason as the inherent limitations and immaturity of the partial, discursive intellect in apprehending higher levels of revelation and intuitive knowledge, challenging superficial readings that perceive the term as a negation of reason. Using an analytic–comparative approach based on primary and secondary sources, the study evaluates these perspectives and frames the stupidity of reason as a methodological and ethical incapacity of intellect in comprehending divine realities. Findings indicate that both thinkers uphold the unity of reason and revelation, yet Javadi stresses methodological rigor and practical application of intellect, portraying stupidity as a relative condition that can be mitigated through intellectual cultivation and soul purification. For Ṣadrā, however, it arises from stagnation, deviation, or veils hindering the actualization of human reason.