How does Chapter 17 use the analogy of a swan to explain the choice between the paths of the good and the pleasant?

In Chapter 17, the analogy of a swan (Maral) is used to illustrate how a wise person should navigate the mixture of good and worldly temptations. Just as a swan is said to be able to drink only the pure milk from a mixture of milk and water, the text advises that courageous and intelligent individuals should cling only to Shreya (the good) and turn away from Preya (the pleasant). As this chapter of the Sai Satcharitra explains, this act of discrimination is the true purpose of human life.