Can you explain the swan analogy used in Chapter 17 to describe the choice between the good and the pleasant?

Certainly. In Chapter 17, an analogy is drawn to a swan, or 'Maral', to illustrate how a wise person chooses between Shreya (the good) and Preya (the pleasant). The chapter states that just as water and milk can be mixed together, so too are Shreya and Preya blended in life. A swan is said to be able to drink only the pure milk, leaving the water behind. Similarly, the text explains that courageous, intelligent, and wise individuals are like this swan; they cling only to Shreya, the path of salvation, and consistently turn away from the worldly temptations of Preya.