By Mathilde De Robien, Aleteia - Why should we control our thoughts?... According to the Desert Fathers, uncontrolled thoughts are the origins of some of the sicknesses of the soul. They identified eight non-psychological sicknesses of a spiritual origin, classified by the monk Evagrius as: greed of any sort, a pathological relationship to sex, a pathological relationship to money, sadness, aggressiveness, acedia, vanity, and pride.