How does Chapter 5 link the concepts of selflessness, pride, and the state of non-duality?

Chapter 5 presents a spiritual progression linking pride, selflessness, and non-duality. It posits that one must first act without pride to achieve their own welfare. By burning the pride of the body, a person makes their life meaningful and is able to ascend the "fort of selflessness." This desireless state is the gateway to the ultimate realization of non-duality. As the chapter illustrates, a wise person who has achieved this no longer experiences a sense of duality, as their own form becomes one with the entire universe.