What are Shreya and Preya, and why is it important to choose between them for a good life?

Chapter 17 explains the concepts of Shreya and Preya as two distinct paths available to a person. Shreya is the path of what is truly good and ultimately beneficial for one's spiritual purpose (Purushartha), while Preya is the path of what is merely pleasant or immediately gratifying. The text warns that a dull-witted person is easily conquered by Preya. The true purpose of human life involves discarding the pleasant but temporary path of Preya to honor the more difficult but ultimately rewarding path of Shreya. As Chapter 17 illustrates, this requires discrimination and strengthening the intellect, much like a swan is said to separate milk from water.