Hippocrates is best known for his famous Oath for physicians, however he also wrote many books of which this is the first - a sort of introductory text. Rather than presenting theory or philosophy he provides practical advice about what medicine works and what doesn't work. It is primarily about knowledge, both of the body and the diseases of the body.

Hippocrates focuses on common diseases, their causes and origins, and specifically mentions the common people as those in whom he is interested. Surprisingly, he highlights the importance of diet, the need to cook meat, and, especially, the use of soups in the diet to moderate the extremes of certain foods.

He compares physicians to pilots who are trying to set a course for health. In doing this there is a discussion of changes in temperature, heat and cold, and the effects on the body of changes in temperature. He also points out that heat is often a symptom of something else. Most importantly he emphasizes the connection between man and nature:
"Wherefore it appears to me necessary to every physician to skilled in nature, and strive to know, if he would wish to perform his duties, what man is in relation to the articles of food and drink, and to his other occupations, and what are the effects of each of them to every one."(sec. 20)

This relatively short book contains practical recommendations for those practicing medicine in Ancient Greece. In spite of the ancient setting of this text it sounds quite modern in its varied concerns regarding man, nature, diet, and the use of a holistic empirical method when dealing with the art of medicine. ( )