true nature of man and this must be determined through his relationship to food, drink, and other practices associated with the human organism (20.3). Therefore, the physician must understand the constituency of food and its effects on the body of the patient he is treating. In Chapters 22–24 the author extends the nature theory to include bodily structures. He also expands his theory of knowledge by advocating the use of analogies to attain an understanding of that which cannot be observed directly within the human organism. Chapters 9–12 In chapters 9–12 the author argues that there is a corresponding relationship between the physician's experience and knowledge and his ability to practice the art of medicine. The greater the general and specific knowledge attained by the physician, the more accurate his diagnostic and therapeutic skills to include preparation and administration of prescriptions or remedies. This is critical because the same illness manifests itself differently in each patient and treatment must correspond to individual symptoms, and not to the common symptoms. This also applies to dietary measures. Thus, in the preparation and administration of remedies or dietary measures, care must be given not only in selecting the quantity and quality of the preparation or remedy, but also to the timing of its administration which must take into account bodily rhythms. The physician, the author argues, must rely upon the reaction of the individual to the treatment. This is indeed a complex process which demands both the education and precision of the physician. Hippocrates argues that even if the ancient art of medicine "does not possess precision in everything; rather, since it has been able to come, by means of reasoning, from profound ignorance close to perfect accuracy, I think it much more appropriate to marvel at its discoveries as having been made admirably, correctly, and not by chance". Date The dates proposed by Schiefsky for On Ancient Medicine span from 440 to around 350 BC. There are a number of considerations which strongly suggest a date in the late fifth century. That the author refers to Empedocles (490–430 B.C.) as motivation of the method he attacks suggests a date not long after his peak of activity. The author's sense of discovery and benefits of technology are characteristic of late fifth-century thought. The idea that human beings through technology rose from savage behavior has parallels in Sophocles' fifth-century work, Antigone. Furthermore, the author's