This Chapter is a dialogue from the Yellow Emperor's Classic of Internal Medicine, specifically Chapter 73, detailing the principles and practice of acupuncture. The Yellow Emperor questions Qi Bo and Lei Gong about proper acupuncture techniques, including diagnosing imbalances of qi and blood, choosing appropriate needle manipulation, and selecting qualified practitioners. The discussion emphasizes the importance of understanding yin and yang, the five elements, and the body's meridians. Finally, it stresses the ethical responsibility of transmitting this knowledge only to worthy individuals.