According to Chapter 8, what is the 'true duty' of human life, and what happens if this duty is ignored?

According to the philosophical section of Chapter 8 of the Sai Satcharitra, the "true duty of human birth is the attainment of the Supreme Self (Paramatman)." The text argues that if this higher purpose is ignored in favor of a life focused only on nourishing the body and seeking sexual pleasure, then the human birth is rendered useless. It drives this point home by comparing such an existence to that of dogs and pigs, which also eat and reproduce. As Chapter 8 explains, a human being is meant to be free and independent, and failing to use this freedom for spiritual realization is seen as a great misfortune, wasting the unique opportunity that a human life provides.