How is the Soul described, and why is its connection to the body an obstacle to detachment?

Chapter 19 describes the Soul (Atma) as fundamentally different from the body; the Soul is changeless, imperishable, self-luminous, and pure consciousness, while the body is perishable. Despite these opposing natures, their affection is described as extraordinary, creating a union where one cannot bear to be without the other. This intense love is identified as the very reason the cycle of worldly existence (Samsara) continues. The ego of identifying with the body, or the thought "I am the body," is a false bondage. To achieve detachment, one must realize the Soul is distinct from the body, senses, and mind, just as a pure crystal remains distinct from the colors it reflects.