The abode of the animal soul (nefesh habahamit) derived from the kelipat nogah in every Jew, is in the heart, in the left ventricle that is filled with blood. It is written, "For the blood is the nefesh" Hence all lusts and boasting and anger and similar passions are in the heart, and from the heart they spread throughout the whole body, rising also to the brain in the head, so as to think and meditate about them and become cunning in them, just as the blood has its source in the heart and .from the heart it circulates into every limb, rising also to the brain in the head.

But the abode of the divine soul is in the brains that are in the head, and from there it extends to all the limbs; and also in the heart, in the right ventricle wherein there is no blood, as is written, "The heart of the wise man is on his right." It is [the source of] man's fervent love towards G‑d which, like flaming coals, flares up in the heart of discerning men who understand and reflect, with the [faculty of] knowledge of their brain, on matters that arouse this love; also [of] the gladness of the heart in the beauty of G‑d and the majesty of His glory [which is aroused] when the eyes of the wise man, that are in his head, i.e. in the brain harbouring his wisdom and understanding, gaze at the glory of the King and beauty of His greatness that are unfathomable and without end or limit, as explained elsewhere; as also the other holy affections (middot) in the heart originate from ChaBaD [wisdom, understanding, knowledge] in the brains.

It is written, however, "One nation shall prevail over the other nation." The body is called a "small city." Just as two kings wage war over a town, which each wishes to capture and rule, that is to say, to dominate its inhabitants according to his will, so that they obey him in all that he decrees for them, so do the two souls— the Divine and the vitalising animal soul that comes from the kelipah— wage war against each other over the body and all its limbs. It is the desire and will of the Divine soul that she alone rule over the person and direct him, and that all his limbs should obey her and surrender themselves completely to her and become a vehicle for her, as well as a robe [instrument] for her ten faculties and three garments mentioned above, all of which should pervade the organs of the body, and the entire body should be permeated with them alone, to the exclusion of any alien influence, G‑d forbid. That is to say, that the three brains that are in the head shall be permeated with ChaBaD of the Divine soul, namely, the wisdom of G‑d and the understanding of Him, by pondering on His unfathomable and infinite greatness; and from them shall be born, through the daat (knowledge), awe in his mind and dread of G‑d in his heart, as well as love of G‑d that shall flare up like a glowing fire in his heart, like flaming coals, so that his soul shall yearn and long, with passion and desire, to cleave to the blessed En Sof, with his whole heart, soul and might, from the very depths of the right ventricle of the heart. The latter would be so thoroughly permeated with love to overflowing, as to inundate the left side as well, to the extent of subduing the sitra achra with its element of the "evil waters," namely, the lust stemming from kelipat nogah, changing it and transforming it from seeking the pleasures of this world to the love of G‑d. Thus it is written, "'With all thine heart— with both your natures." That is to say, that the person shall steadily rise to attain to the degree of "abundant love," a supreme affection surpassing that of "ardent love" that is comparable to burning coals.

This is what is called in Scripture "love of delights," which is the experience of delight in G‑dliness, of the nature of the world to come. This delight is in the brain of wisdom, in the intellectual pleasure of comprehending and knowing G‑d, to the extent that one's intellect and wisdom can grasp [Him]. This is the element of "water," and "seed," i.e., light that is sown in the holiness of the divine soul that converts to good the element of "water" in the animal soul, from which the lust for mundane pleasures had been previously derived.

Thus it is written in Etz Chayim, Portal 50, ch. 3, on the authority of the Zohar, that the evil is converted into, and becomes, completely good, like the good nature itself, through the shedding of the soiled garments, the pleasures of this world, in which it had been clothed.

So, too, shall the other middot in the heart, the offshoots of awe and love, be dedicated to G‑d alone; and the faculty of speech that is in his mouth, and the thought that is in his mind, shall be entirely and solely the instruments of the "garments" of thought and speech of the divine soul alone, namely, meditation on G‑d and His Torah, which shall be the theme of his speech throughout the day, his mouth ceaselessly studying [it]; and the faculty of action centered in his hands, as also in the rest of the 248 organs, shall function exclusively in the performance of the commandments, which is the third garment of the divine soul.

However, the desire of the animal soul which is derived from the kelipah is the very opposite— and it is for the good of man, that he may prevail over her and vanquish her, as in the parable of the harlot in the holy Zohar.