Mullā Ṣadrā established the concept of substantial motion in the nature. In his philosophy, the soul is also considered one of the entities in motion. Given the denial of motion in immaterial entities by renowned philosophers (including Mullā Ṣadrā), a contradiction is perceived between the immateriality of the soul and its mobility. Therefore, the essence and nature of motion, particularly its depiction in the soul, have been subjects of contention. This article, after elucidating the meaning of motion and the essence of substantial motion, analyses various solutions proposed by philosophers to reconcile the immateriality and mobility of the soul, and critiques them all. After proving the possibility of combining immateriality and motion in the soul, we re-examine how this is actualized in the soul. Ultimately, we have identified five types of motion for the soul in the words of philosophers and in the history of Islamic psychology (‘ilm al-nafs) and critiqued them. The soul is immaterial, but substantial motion within it is also possible. This motion occurs in a continuous manner.