The Demo Site

The soul (nafs) employs the body to attain its goals. The soul has also other names, including spirit (ruh), intelligence ('Aql), and heart (qalb) although these terms have other usages. The primary faculties of the soul are :

The value of these forces is obvious. Reason distinguishes good and evil: ghadab (anger) helps defend against aggression: sexual attraction maintains the survival of the human species; and imagination allows visualization of universals or particulars. Reason is man's guiding angel. Anger brings violence; passions (hawā) encourage immorality; and imagination provides material to formulate demoniac plots and machinations. If reason controls the other faculties, it moderates excesses and ensures useful performance. 

Allah says in surat Ash-Shams: And by nafs, (soul), and Him Who perfected him in proportion; Then He inspired him corruption and its righteousness; Indeed he succeed who chooses to purify his ownself; and indeed he fails who corrupts his ownself. The soul is in a continuous jihad (struggle) between these four powers for domination. The victorious trait determines the soul's inclination.