The attribution of intellection and understanding to the “heart” in the Qur’an raises a hermeneutical question concerning the relationship between cognition and the human being’s inner state. This study asks whether the heart in these verses is merely a metaphor for the intellect or represents a cognitive–existential dimension of the human subject. Employing a qualitative, descriptive–analytical method, the research examines the semantic network of the Qur’anic verses concerning the heart at three interpretive, semantic, and hermeneutical levels. It critically draws on lexical sources, authoritative Qur’anic commentaries, Imāmī traditions, and mystical and philosophical readings. The findings demonstrate that the heart is neither a rival to the intellect nor a bodily organ replacing the brain; rather, it is a dimension in which cognition, volition, faith, and value orientation converge. Sickness, deviation, hardness, locking, sealing, and blindness represent distinct forms of cognitive–existential obstruction, whereas soundness, penitential return, and tranquility signify openness to truth. The study’s principal contribution is a four-component model comprising reception, cognitive processing, existential orientation, and cognitive stability or obstruction.