Having gained an understanding of the three totally impure Kelipot (husks/shells/peels) we turn our attention to understanding the Kelipah Nogah (the translucent / glowing husk) and as it manifests itself within the animal soul of the Jew.
The Alter Rebbe introduces us into the idea that the animal soul of the Jew can be directed in two ways. It has the potential to elevate us higher, or to bring us lower, depending on how we use it. We can use it for degrading things even if they are permitted(!), or we can use it to elevate everything we come into contact with!