What does Chapter 8 say is the primary duty of a human being, and what is the consequence of ignoring it?

According to the philosophy presented in Chapter 8, the primary and true duty of a person is the attainment of the Supreme Self, or Paramatman. The text emphasizes that human beings are free and independent, and the true success of birth is the realization of the Eternal. If this duty is ignored in favor of a life focused only on nourishing the body and sensual pleasures, the chapter states that this human birth is rendered useless. It posits that such an existence is no different from that of dogs and pigs, which also fill their bellies and reproduce, thereby missing the unique spiritual opportunity offered by human life.