This Chapter is a dialogue from the Yellow Emperor's Classic of Internal Medicine, specifically Chapter 75, where the Yellow Emperor instructs Lei Gong on advanced medical principles. The discussion centers on understanding the "Three Yang," a complex energetic force whose imbalance causes various illnesses. The Emperor emphasizes the importance of connecting medical knowledge with celestial and earthly patterns, highlighting the interconnectedness of yin and yang, and the seasons. The ultimate goal is to achieve a deep understanding of the "Way" to improve medical practice and benefit humanity. Lei Gong's questions reveal his need for deeper understanding of the subtle energetic forces underlying disease.