Human soul is an immobile variable (mojarrad) that at the same time posses the feature of movement (or flux) in its essence. The commonest proof for denying motion in incorporeal beings is the “argument of potentiality and actuality”, that as we all know is an invalid argument.
Invalidity of this argument is for impossibility of containing simultaneously both deficiency (potentiality) and sufficiency (actuality) in one simple (naive) being. But if two different being contain these aspects, then there will be no contradiction.
If we deny this argument, then it will be possible for one simple being (like human soul) that posses simultaneously potentiality and actuality, especially if we consider that these two features are secondary intelligible of philosophy.