What does Chapter 17 say about the role of human effort (Purushartha) and the necessity of a Guru in overcoming the cycle of worldly existence?

In Chapter 17, true human effort, or Purushartha, is defined as the act of consciously discarding Preya to honor Shreya. This effort begins when a person, exhausted by the sorrows of worldly existence (Samsara), seeks to end the cycle. The text advises struggling for the sake of Shreya by strengthening one's intellect. However, it also highlights the limitations of individual effort by stating that the Guru can show the way to a place where even the intellect and the Vedas cannot enter. The Guru's role is critical in helping to overcome deep-rooted obstacles like lust and anger, which disrupt the path to knowledge and cannot be conquered by intellect alone.