According to Chapter 19, what is the path to liberation and what is the primary duty of human birth?

Chapter 19 defines the duty and fulfillment of human birth as the attainment of eternity, fearlessness, liberation, independence, and the Supreme Self. The path to achieving this is laid out very clearly. The chapter emphatically states that "there is no liberation without knowledge." It further explains that knowledge itself cannot be attained without detachment. This crucial sense of detachment only arises when the mind begins to perceive the world as transient and impermanent. Therefore, the progression outlined in Chapter 19 is that recognizing the world's transient nature leads to detachment, which opens the door to knowledge, the only means to liberation.