Chapter 17 discusses the concept of 'Purushartha'. How is this concept explained in relation to Shreya, Preya, and the suffering of worldly existence?

In Chapter 17, 'Purushartha' is described as true human effort or the true purpose of human life. It is directly linked to the choice between Shreya (the good) and Preya (the pleasant). The chapter explains that discarding Preya to honor Shreya is the ultimate Purushartha. This realization often arises after one has suffered the three unendurable torments (Tritapa) of the incessantly spinning wheel of worldly existence (Samsara). As the text from Chapter 17 illustrates, it is when a person, exhausted by sorrow, begins to search for a way to stop this cycle that true Purushartha is born, leading them to choose the successful means for their own true self-interest, which is the path of Shreya.