Zeir Anpin has three mochin: chochma, bina, and between them, daat - which contains chasadim and gevurot - two crowns.

Wisdom, understanding, and knowledge are the three major faculties of the human mind. They are modeled after and come from the corresponding faculties of the supernal mind of Zeir Anpin.

Chochma occupies the right side of the mind, bina the left. Daat is the balancing energy that lies between them. From it come decisions between the different sides of an issue. In order to be able to do this, it must be composed in and of itself of both right and left dynamics. The chesed/right and gevura/left aspects are called crowns. They jump down a step, from the shoulders of Abba and Imma, surrounding and crowning daat.

When Adam sinned, he caused the moach of daat to descend between the two shoulders of Zeir Anpin, into the upper third of tiferet, until the chest. There, the chasadim separated and went into the right shoulder and the gevurot went into the left shoulder.

Daat left its proper place in the mind and became part of the body.

Daat left its proper place in the mind and became part of the body. This caused it to diminish in quality. A simple way of understanding this is to say that the mind, which was meant to soar above and probe celestial vistas, sold out and became used for mundane pursuits.

The test was with the tree of daat/knowledge, as mentioned, because daat decides. Resisting eating from the energy of mixed knowledge would have immediately perfected their mind and given them a ticket to eternal utopia. Partaking of the tree caused the daat to become defected and brought it down to places it was never meant to operate in. Learning and living the Torah fixes and elevates the daat. The general idea behind how it does this is that it properly balances and puts in synch the right and left side of the mind. This results in the person enjoying a perspective of reality according to what it truly is. In such a headset, one can see how important each idea and thing is relative to itself and to everything else. From this mentality, one can understand how to harmonize his life and the world around.

Since Cain and Abel were born after Adam sinned, Cain was from the gevurot in the left shoulder after they arrived there and became unable to give off light as they did when part of the moach itself above.

Another negative result was that while the daat was in the head above where it belongs, the chitzoniyut [externality] of the nefesh came from the bone and flesh of the head itself. For, as is known, every soul has a penimiyut [inner aspect] and chitzoniyut [external], its clothing. Thus it was that the penimiyut was from the gevurot of the moach daat and was related to its chitzoniyut, which was from the bone and flesh of the left side of the head.

However, once the moach daat descended, the peniminiyut of the soul of the root of Cain remained in the moach of gevurot in the daat, but the chitzoniyut was now from the left shoulder-limb, and they were no longer related to each other.

It also causes one to be 'two-faced', besides dividing between family and friends.

This is the cause of an ailment that plagues many of the Cain root: Self-separation, fragmentation, and even sometimes schizophrenia. It also causes one to be 'two-faced', besides dividing between family and friends.

The ultimate source of this itself is the root of Cain in the world of Tohu [chaos]. There, the lights are separate from the vessels… (Eitz Chaim, Shaar HaShemot) The tikun process involves lessening the light in order that it should fit in the vessels. This is done primarily through nullifying the ego. In terms of the mind and shoulder mentioned here, they must be 're-united'. This involves aligning one's actions to his mind - his understanding of how he should act. "Practice what you preach."

Furthermore, the peniminiyut no longer gives off light as it once did - before while in the head.

The second lacking on the level of chitzoniyut is that they are now from the bottom, that is the shoulder, and not from their rightful place: galgalta [the skull].

Even though a person in this world does not have the ability to correct these defects even through mitzvahs [good deeds], still, performing mitzvahs is to his merit.

Even though the good things we do cannot change and correct everything that needs fixing, it is good to do them. For they aid the process of all corrections eventually coming to full fruition.

For in the time of Mashiach, these defects will be rectified and the daat will return to its proper place in the head. The peniminiyut of the soul will give off light as it did previously, and the chitzoniyut will come from their proper location: galgalta.

I don’t know if my teacher told me whether the chitzoniyut from the left shoulder will also remain there in the time of Mashiach with the peniminiyut of the soul, since they were joined together in this world, or just the opposite.

Furthermore, just as the daat descended between the shoulders as a result of Adam’s sin, so too did the partzuf of Leah descend from the backside of the daat of Zeir Anpin, which is her proper place. After the sin of Adam, she also descended to the back side of the shoulders, since Leah is from the malchut of Imma, which is in the daat of Zeir Anpin, enclothed within yesod Imma. (Eitz Chaim, Shaar Leah v'Rachel)

[Translation and commentary by Perets Auerbach.]