What philosophical argument does Chapter 12 make about the role of a Guru in removing the illusion of duality?

Chapter 12 presents the Guru, specifically Sai Baba, as the ultimate remedy for the illusion of duality and the struggles of worldly existence. The text refers to Sai as the "embodiment of Truth, Consciousness, and Bliss" who "stills the waves of worldly existence." A key philosophical point made in this chapter is that through the "knowledge of non-duality," the Guru can remove the "obsession with duality even from the dull-witted." He is also described as the Agastya who can drink the ocean of worldly existence and the sun that dispels the darkness of ignorance. This establishes the Guru as an essential guide who is inseparable from the Supreme Soul, as explained in Chapter 12.