"The Almighty has created one thing opposite the other."

Just as the divine soul consists of ten holy Sefirot and is clothed in three holy garments, so does the soul which is derived from the sitra achra of the kelipat nogah, which is clothed in man's blood, consist of ten "crowns of impurity." These are the seven evil middot which stem from the four evil elements mentioned above, and the intellect begetting them which is subdivided into three, viz., wisdom, understanding and knowledge, the source of the middot. For the middot are according to the quality of the intellect. Hence a child desires and loves petty things of inferior worth, for his intellect is too immature and deficient to appreciate things that are much more precious. Likewise is he provoked to anger and vexation over trivial things; so, too, with boasting and other middot.

Now these ten unclean categories, when a person meditates in them or speaks them, or acts by them, his thought — which is in his brain; and his speech—which is in his mouth; and the power of action— which is in his hands, together with his other limbs— all these are called the "impure garments" of these ten unclean categories wherein the latter are clothed at the time of the action, speech or thought. It is these that constitute all the deeds that are done under the sun, which are all "vanity and striving after the wind," as interpreted in the Zohar, Beshallach, in the sense of a "ruination of the spirit...."

So, too, are all utterances and thoughts which are not directed towards G‑d and His will and service. For this is the meaning of sitra achra— "the other side," i.e. not the side of holiness. For the holy side is nothing but the indwelling and extension of the holiness of the Holy One, blessed be He, and He dwells only on such a thing that abnegates itself completely to Him, either actually, as in the case of the angels above, or potentially, as in the case of every Jew down below, having the capacity to abnegate himself completely to the Holy One, blessed be He, through martyrdom for the sanctification of G‑d.

That is why our Sages have said that "Even when a single individual sits and engages in the Torah the Shechinah rests on him' and "On each [gathering of] ten Jews the Shechinah rests" always.

However, that which does not surrender itself to G‑d, but is a separate thing by itself, does not receive its vitality from the holiness of the Holy One, blessed be He, that is, from the very inner essence and substance of the holiness itself, but from "behind its back," as it were, descending degree by degree, through myriads of degrees with the lowering of the worlds, by way of cause and effect, and innumerable contractions, until the Light and Life is so diminished through repeated diminutions, that it can be compressed and incorporated, in a state of exile as it were, within that separated thing, giving it vitality and existence ex nihilo, so that it does not revert to nothingness and non-existence as it was before it was created.

Consequently, this world, with all its contents, is called the world of kelipot and sitra achra. Therefore all mundane affairs are severe and evil, and wicked men prevail, as explained in Etz Chayim, Portal 42, end of ch. 4.

Note: To be sure, there are contained in it [this world] the ten sefirot of the world] of Asiyah (Action) of the side of holiness, as is written in Etz Chayim, Portal 43, and within these ten sefirot of Asiyah are the ten sefirot of Yetzirah (Formation), and in them the ten sefirot of Beriah (Creation), and in them the ten sefirot of Atzilut (Emanation), in which abides the light of the blessed En Sof. Thus the light of the blessed En Sof pervades this lower world through being clothed in the ten sefirot of the Four Worlds, namely those of Atzilut, Beriah, Yetzirah and Asiyah, as explained in Etz Chayim, Portal 47, ch. 2, and in Sefer ha-Gilgulim, ch. 20.

However, the kelipot are subdivided into two grades, one lower than the other. The lower grade consists of the three kelipot which are altogether unclean and evil, containing no good whatever. In the "chariot" of [the prophet] Ezekiel they are called "whirlwind," "great cloud." .. . From them flow and derive the souls of all the nations of the world, and the existence of their bodies, and also the souls of all living creatures that are unclean and unfit for consumption, and the existence of their bodies, as well as the existence and vitality of all forbidden food in the vegetable kingdom, such as orlah and "Mixed seeds in the vineyard,..." as explained in Etz Chayitn, Portal 49, ch. 6, as also the existence and vitality of all actions, utterances, and thoughts pertaining to the 365 prohibitions and their offshoots, as is explained ibid., at the end of ch. 5.