What comparison does Chapter 8 make between humans and animals, and what is the ultimate success of human birth?

In Chapter 8, a clear distinction is drawn between human potential and animal existence. The text argues that if a person's life is solely dedicated to nourishing the body and sexual pleasure, their birth is useless and no different from that of a dog or a pig. It states that dogs also fill their bellies and reproduce, questioning wherein the greatness of the human body lies if it is used for the same ends. According to Chapter 8, the true success of human birth is the realization of the Eternal. A human being is uniquely free and independent, and using this freedom to understand our spiritual origin is the primary duty and achievement of this life.