Hippocrates (c460-375 BC) came from a family of doctors and underwent the standard training at the local ‘asclepeion’ temple – where priests treated the sick using religious magic, dream interpretation and snake-worship.
Yet, Hippocrates rejected such supernatural causality and argued for a rational, bodily explanation for illnesses. His belief was that the body had four ‘humours’ – black bile, yellow bile, blood and phlegm – and that these fitted into a sort of elemental Venn diagram of hot, cold, wet and dry. Disease was the result of imbalances in these humours caused by diet, climate and living habits, and had nothing to do with meddling gods.
But how did he diagnose what ailed a patient? Well, he advocated the analysis of urine, faeces, pus, mucus, vomit, sweat and earwax, and was even prepared to taste some of them. He suggested bitter earwax was a sign of good health, but sweet wax was cause for alarm.
Humorism was dominant in medicine until well into the mid-19th century, giving rise to many stories of blood-lettings, purgative vomits, and seemingly barbaric treatments dished out to peasants and princes alike. But Hippocrates had actually been a cautious, gentle doctor and had vigorously demanded high standards of ethics from his followers, which is why modern doctors honour his name by taking a Hippocratic Oath to do no harm.