From Faculties to Functions: Fakhr Al-Dīn Al-Rāzī’s Critique of Internal Senses

One of the basic questions of the classical theory of soul is the theory of internal senses, which received its most elaborate form under Avicenna. While he effectively revised this theory, which he inherited as it was laid out, he expounded upon it according to his own philosophical inclinations, thereby making significant additions on intricate matters like the number and appellation of the internal senses by introducing new distinctions and classifications. Over time, Avicenna's novel framework concerning the theory drew several criticisms by his successors. An important critique was leveled by Fakhr al-Din al-Razi. The first point of al-Razes contestation was his critique of the arguments for the existence of each internal sense as a separate faculty. Al-Razi supposed that the soul could perceive all objects of perception without recourse to independent faculties, each of which was designed for a separate function. Second, he criticized the narrative that plotted the brain for internal senses. While this critique comprises the main subject of this study, it will also try to clarify those of its aspects that are related to greater epistemological and psychological questions, like the nature of the soul, the character of the soul-body relation and interaction, the nature of perception, the degrees of abstraction, the relation of the soul with the particulars, and its bearing on them.