This Chapter is an excerpt from the Yellow Emperor's Classic of Internal Medicine, specifically Chapter 78, which discusses four common errors made by physicians. The Yellow Emperor and Lei Gong explore the reasons for treatment failures, highlighting the importance of focused attention, understanding the patient's circumstances, a thorough investigation into the illness's origins, and a solid grasp of fundamental medical principles. Failure to adhere to these principles leads to inaccurate diagnoses, ineffective treatments, and ultimately, harm to the patient. The text emphasizes the necessity of self-awareness, humility, and a comprehensive approach to medical practice.