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

Chapter 19 outlines that the fulfillment of the soul and the principal duty of human birth is the attainment of eternity, fearlessness, liberation, independence, and the Supreme Self. The chapter states a clear progression for this path: there is no liberation without knowledge, and knowledge cannot be attained without detachment. The spark for detachment arises only when the mind perceives the world as transient. As long as ego regarding the body, mind, and intellect persists, the sense of being a 'doer' and 'enjoyer' remains, making the experience of pleasure and pain unavoidable and hindering the path to true liberation.