The Relationship between Soul and Faculties from the Viewpoint of Avicenna and Mulla Sadra

Considering a single soul for every single person conducting actions and perceptions with different faculties, Avicenna and Mulla Sadra, like some other philosophers, have rejected multiplicity of soul in human being. The research findings show that, from Avicenna’s point of view, soul is the cause, recruiter, and conqueror of faculties, but faculties are the effect, servant, and conquered units of soul. Although, in terms of concept and application, he regards the faculties apart from the soul, he attributes all their actions to the soul, and considers it the cause of all actions and perceptions.Holding that the relation between self and faculties is causality inthe sense of disposition (tashaun), Mulla Sadra does not consider causality in the sense of Peripatetic sufficient to attribute the faculties’ actions to the soul in the true sense. Therefore, he regards the faculties as the manifestation of the dimensions of the soul and a disposition of its own, which have no independent ruling, and hence, the actions of faculties are, in fact, the action of the soul, and the soul in its unity is its entire faculty.