Thus we find here two things that exist on all the different levels. The first is the Line of Measurement, which is what causes successive degrees of concealment. The second is the existence of good and evil, which are what is left of the initial perfection depending on the degree of the concealment and the extent of the deficiency. You must understand that the deficiency caused by the Tzimtzum is what is called the root of the roots of evil.
In the end, when the deficiency becomes completely overwhelming, the result is that evil becomes manifest. Thus we see that the Tzimtzum is the root of the axiomatic law that eventually brings into being a realm based on good and evil. This law consists of what remains of the original perfection together with the deficiencies that came into being afterwards. What remained of the original perfection later brought forth the entire realm of holiness, which consists of the Sefirot in all their different aspects, while the deficiency brought about a new consequence, just as deficiency itself was an innovation. This new consequence is the Other Side, as we will discuss further below.