If you asked an educated physician in 30 AD why a person was ill, you would usually hear a story about fluids. Four of them — blood, phlegm, yellow bile, and black bile — were thought to compose the body. Health was proportion. Disease was a flood, a drought, or a misplacement of one humor.
This was not folklore pretending to be philosophy. It was the dominant learned model of the Greco-Roman world, with roots in earlier Greek writing (especially the Hippocratic On the Nature of Man) and a long afterlife: it still shaped European medicine in the Renaissance. It lasted because it was visible. Anyone could see blood, mucus, and bile. Heat and cold, wet and dry, were felt every feverish night.
The four, at a glance
Select a humor. Each pairing of quality, season, element, and temperament gave the physician a script: cool the hot, dry the wet, warm the winter patient, calm the choleric.
Blood (Haima)
- Season / element
- Spring · Air
- Temperament
- Cheerful, generous, talkative, rosy.
- When in excess
- Fevers, flushing, nosebleeds, over-excitement.
- Typical response
- Bleeding, cooling foods, rest from wine and meat, spring purges.
Why the model felt true
- Fevers look like excess heat and often flush the face — “too much blood.”
- Winter coughs pour phlegm. Spices and steam seem to thin it.
- Vomiting can bring up bitter yellow. Anger comes with a burning gut.
- Depression and constipation can arrive together in a cold season — “black bile,” a humor more inferred than seen, but narratively powerful.
Treatments were logical inside the system. Bleed the sanguine fever. Pepper the phlegmatic chest. Pour cold water on summer inflammation. Offer wine, music, and company to the melancholic. When the patient improved — as self-limited disease often does — the theory collected the credit.
Not every physician agreed. Asclepiades of Bithynia had taught Rome that the body was particles and pores, and that baths, diet, and wine beat heroic purging. Celsus records both the mainstream and the dissent.
Temperament: character as physiology
Humoral language leaked into personality. A sanguine friend was convivial; a choleric official, sharp; a phlegmatic neighbor, slow to take offense; a melancholic scribe, exact and sad. The four temperaments outlived the clinic. They still haunt personality quizzes. In antiquity they were not metaphors. They were medical forecasts: this body will tend toward these diseases, and should eat this way in this season.