What is the connection between ego, knowledge, and liberation as described in Chapter 19?

Chapter 19 establishes a clear progression from ego to liberation. It states that as long as a person identifies with the body, mind, and intellect—maintaining the ego of being a "doer" and "enjoyer"—the experience of pleasure and pain is unavoidable. To break this cycle, the chapter teaches that there is no liberation without knowledge, and knowledge cannot be attained without detachment. This detachment begins when the mind truly perceives the world as transient. Therefore, according to Chapter 19, letting go of ego and gaining knowledge through detachment is the required path to attain the Supreme Self, which is the ultimate fulfillment and duty of human birth.