These rules are drawn from extensive reading and over 60 years of teaching and practicing internal medicine. The rules are directed at those entering medicine and at those in practice who see patients in primary care or family medicine. The book is dedicated to Sir William Osler who admonished doctors to "'treat the patient with the disease" not just the disease. Large numbers of first contact patients do not have a definable medical disease but they do have hidden physical symptoms. Uncovering the cause of these symptoms of unknown origin requires careful listening and observation. These 374 rules provide guides and suggestions for discovering the nature of these symptoms, emphasizing the need for an understanding, collaborative, and accepting relationship between doctor and patient. Listening to the "life narrative" of the patient often leads to an understanding of the origin of the patient's symptoms. Many diseases and causes of symptoms cannot be "seen" but must be heard from the patient's story and history.