Galen’s First Commentary on Hippocrates

...een the two should be determined as follows. When many people are seized by a single disease at the same time, the cause must be attributed to what is most common and what we all use most. This is the air we breathe. It is clear that the personal regimen regimen: a person’s specific habits of diet, exercise, and daily living of each individual is not the cause. This is because the disease attacks everyone in succession: the young and the old, women and men, those who drink wine and those who drink only water, those who eat barley cakes and those who eat bread, those who exercise little and those who work hard. Therefore, the regimen cannot be the cause when people living in every possible way are seized by the same disease. However, when diseases of all different kinds occur at the same time, it shows that the specific regimen of each person is the cause.

In this passage, Hippocrates states that the condition of the atmosphere original Greek: "κατάστασιν" (katastasin); Latin: "coeli statum." This refers to the overall state of the weather and air quality. is the cause of all epidemic diseases, rather than a person’s diet. Yet, it is also possible for the drinking of foul water to cause a disease common to everyone. This has been recorded and...