Chapter 17 uses the analogy of a swan separating milk from water. How does this relate to the choice between Shreya and Preya and the concept of 'Purushartha'?

The analogy in Chapter 17 of a swan (Maral) drinking only pure milk from a mixture of milk and water illustrates how a wise person should approach life's choices. Just as the swan discriminates, courageous and intelligent individuals are meant to cling only to Shreya (the Good) and turn away from Preya (the Pleasant). This act of discarding Preya to honor Shreya is defined as the true purpose of human life, or Purushartha. Therefore, the analogy serves as a powerful metaphor for using one's intellect to make a discerning choice for spiritual salvation, which is the highest human effort.