How does Chapter 17 define the concept of 'Purushartha' and connect it to overcoming the suffering inherent in worldly existence?

In Chapter 17, 'Purushartha,' or true human effort, is defined as the act of discarding the pleasant path (Preya) to honor the good path (Shreya). The text explains that this effort becomes paramount because worldly existence (Samsara) is an incessant wheel of suffering, causing unendurable torments. It is when a person, exhausted by this sorrow, begins to search for a way to stop this cycle that Purushartha is truly born. This effort involves strengthening one's intellect to resist obstacles on the path of Shreya and choosing the means for one's true self-interest, marking the beginning of the journey to transcend suffering.