The soul enclothed within the body is a reflection of the Divine Form, called the tzelem, or tzelem  Elo-him. This tzelem Elo-him may be described as the spiritual mold of man's physical form, linking his body and soul. This mold is derived from the configuration of the  sefirot, which structure the worlds through which the soul descends on its journey down into the body.
 
At the same time that the soul's outer dimension reflects the configuration of the sefirot, the inner dimension of the soul reflects the  Infinite Light, which illuminates the sefirot. This reflection is called the demut Elo-him (the image of G-d). Thus man includes all of Creation within him, from the loftiest spirituality to the most mundane physicality.

Viewed from the point of view of man's service to G-d, these levels of soul may be described as five ascending levels of awareness of, and communion with, G-d. They are called (in ascending order) nefesh, ruach, Neshamah, chayah and yechidah. Regarding these levels of soul, the  Zohar states that when a person is born, he is given a nefesh from the world of  Asiyah, the lowest world, representing the greatest concealment of G-d. If, through his divine service and proper action, he makes himself worthy, he is then given ruach on the plane of Yetzirah. With greater effort, he can earn the revelation of neshamah, paralleling the world of Beriyah. If he purifies himself greatly, he may be able to attain the level of chayah paralleling Atzilut, and even yechidah -- the G-d consciousness of the level of Adam Kadmon and beyond. ("Beyond," because the level of soul called yechidah in essence transcends all the worlds, since it is never separated from G-d. It is described as being "truly part of G-d above," and as "a spark of the Creator enclothed within a spark of the created").

The soul enclothed within the body is a reflection of the Divine Form

Nefesh, the lowest level of consciousness, is awareness of the physical body and the physical world, the world of Asiyah -- the world of Action. However, this awareness of the physical body is not awareness in a passive sense; it is merely an observation of the facts. On the contrary, the nefesh is in fact the life-force of the body, and it is precisely because it is the life-force of the body that the nefesh has an awareness of the body. This physical awareness is a result of the enmeshing of the nefesh with the body. Now, although the nefesh is the life-force of the body, this does not mean that the nefesh creates the body. The body was and is created by G-d, just like everything else. After G-d created Adam's body "from the dust of the earth", He blew into Adam the breath of life.² This is the nefesh -- the life-force-- that was blown into the body.

The divine service associated with the level of nefesh is acknowledgment of, and submission to, the supreme authority of G-d, particularly in reference to the fulfillment of the commandments. It is therefore called "accepting the yoke of Heaven" -- kabbalat ol malchut shamayim.

ruach

Ruach is the next level of soul -- a higher plane of consciousness than the rank of nefesh. The world (i.e. level of revelation of G-dliness) corresponding to ruach is the world of Yetzirah. The primary manifestation of ruach is in the emotions, just as the primary activity of the six sefirot of Zeir Anpin (from  chesed to  yesod) is in the world of Yetzirah. In terms of Divine service this entails arousing the complementary emotions of love and awe of G-d.

Love and awe of G-d are aroused by contemplating the divine energy which forms and maintains the world of Yetzirah, and by observing the tremendous self-nullification of the angelic beings which inhabit it. Although the intellect may be used extensively on this level of soul, nevertheless, the primary focus of the intellect here is contemplation in order to arouse the emotions. The Talmudic sages therefore refer to it as "the toil of the heart", through which one comes to love G-d with all one's heart. Nevertheless, this is a lower level of love, since it is generated by contemplating lower levels of G-d's creative energy.

neshamah

The primary activity of the neshamah is in the conceptual grasp of the intellect, as the verse states, "and the soul (nishmat) form the Almighty gives them understanding".³ The level of neshamah contemplates the manifestation of Divine energy in the world of Beriyah. Just as in the world of Beriyah, the primary sefirah is  binah, so too in the soul -- the primary activity is understanding. Unlike the world of Yetzirah, the world of form and relationship, the world of Beriyah is nascent divine energy. It is the notion of coming into being from nothingness, rather than structured, quantified existence. Thus one of the primary meditations of the neshamah is the concept of continuous creation (the coming-into-being) and sustenance of life and existence

one of the primary meditations of the neshamah is the concept of continuous creation (the coming-into-being) and sustenance of life and existence

The aspect of the soul called chayah gazes upon the Divine energy of the world of Atzilut. Whereas the primary activity of the level of neshamah is to use intellectual comprehension in order to come to communion with G-d as the Creator of the worlds, the level of chayah communes with G-d as He transcends the worlds. Here the soul's knowledge is not in the immanence of Divine attributes which identify the nature of the Divine energy manifested in Creation, but rather with knowing what G-d is not -- i.e. how He is not limited or defined by the finite universe. Thus the soul merges into a state of complete nullification of the ego. There is no self-seeking and no self-identity outside of G-d.  Chayah is called loving G-d "with all one's being".⁵ This is knowledge of the absolute truth of things.

yechidah

Yechidah corresponds to the level of soul called Adam Kadmon. Just as the sublime, pure and transcendent world of Adam Kadmon, cleaves to and reflects the original Infinite Light (Or Ein Sof), so too does the level of yechidah. This is the essence of the soul which is naturally and immutable bound to the Holy One. Rabbi Shimon bar Yochai declared, "Throughout the days of my connection to this world, I was bound to the Holy One Blessed Be He with a single knot...at one with Him"; this is the level of soul revealed at the moment of self-sacrifice or martyrdom for the sake of G-d, His  Torah, or His people.

From the "Fiftieth Gate" edition of the Zohar, Introduction.

Republished from www.kabbalaonline.org