What comparison does Chapter 8 draw between humans and animals when discussing the purpose of life?

Chapter 8 draws a sharp comparison between humans and animals to emphasize the unique potential of human birth. It argues that if a person's life is solely dedicated to nourishing the body and engaging in sexual pleasure, then that human birth is essentially useless. The text explicitly asks what dogs and pigs lack in terms of mere survival, noting that they also fill their bellies and reproduce. As explained in this chapter, if a human life is reduced to the four basic activities of eating, sleeping, fear, and mating, then there is no discernible difference between that human and a dog. This comparison serves as a powerful call to action, urging readers to seek the higher purpose of human existence, which is the attainment of the Supreme Self.