Imam Khomeini explains the matter in his famous book of "an exposition on Forty Hadith" as saying:
But they have rather advocated for controlling and bridling them and making them function under the command of reason and Divine Laws.
For each one of these powers struggles to dominate others and win its goal, whatever mischief, chaos, and confusion may be stirred up.
For instance, the obstinate bestial self is determined to reach its goal even if it is resolved on committing adultery with married women in the Holy Ka’bah.
Intractable power of passion arouses the self to win its objective even if it is contemplating to kill prophets and the friends of God.
And the power of imagination, while devising satanic instruments, wants to go its own way, to cause corruption of the whole climate on earth, and to create chaos and disorder in the world.
The great prophets of God were sent to this world with the light of Divine Laws, Imam further explained.
God revealed to them heavenly books, so that they may prevent people from indulging into extravagances and immoderations, and bring the human self under the control of reason and the law of Shari’ah.
To bridle the human self is essential so that it may not exceed the measures of reason and Shari’ah.
Hence, every individual who subordinates himself to the Divine Laws and principles of good sense is fortunate, and it is he who attains salvation.
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