What is the difference between the soul (ruh) and the self (nafs), what is the definition of each, and which of them is stronger in controlling the mind and body?

The reality of the soul is among the matters of which Allah alone has knowledge. The soul (ruh) and the self (nafs) are synonymous and interchangeable; thus, it cannot be said which of them is stronger in controlling the mind and body. Ibn al-Arabi said: "The soul is a creation of Allah Almighty, which He placed in bodies, thereby giving them life." Ibn Taymiyyah said: "The soul that manages the body and departs from it at death is the soul breathed into it, and it is the self that departs from it at death." He supported this with verses and hadiths that describe the soul and the self with the same meaning at the time of death and sleep.