The essay "In Hippocratis de natura hominis librum commentarii III" helps to clarify the views of Galen on the issues of diagnosis and treatment of diseases. Using the example of this work, medical historians have a clear picture of the succession of Hippocrates' ideas in the medicine of Galen. This work sheds light on Galen's views on the physical nature of the human body: According to Galen, a person's condition is determined by the balance of the four main fl uids, and the physical foundation of living creatures is four primary elements. The primary elements are in constant interaction with each other to form a combination that leads to one's state of health or disease