This Chapter is a dialogue from the Yellow Emperor's Classic of Internal Medicine, specifically Chapter 55, "The Spiritual Pivot – Reversal and Conformity." The conversation between the Yellow Emperor and Bo Gao explores the principles of acupuncture, emphasizing the importance of timing. Bo Gao explains that effective needling depends on understanding the interplay of qi, the pulse, and the disease's progression. He stresses the ideal scenario is treating illness before symptoms manifest, while cautioning against treatment during peak illness or when the pulse and disease contradict each other. The superior practitioner anticipates and prevents disease, rather than reacting to its full development.