“‘…not here for bloodletting then? Well, if you’re a bit phlegmatic, I could do you a bit of cupping. Let’s get those humors back in balance, eh?’ the barber continues. ‘I’ll get the cups and light a fire.'”
Want to hear something humorous? Blood. If you take a jar a blood and leave it out on the counter, apart from being really creepy, you will discover it separates into four different layers of goo: red, black, clear(ish), and yellow(ish) froth. Go ahead and try it. It is fascinating. I won’t ask where you get the blood from. And once you’ve done it, you’ve got the basis for nearly 2,000 years of medical science.
According to humorism, which dates back to the ancient Greeks, the human body is made of four liquids – or humors – in various different levels. The humors were blood, black bile, yellow bile, and phlegm. And the balance of these four humors gave rise to both personality and illness.
(By the way, blood isn’t really made of those four humors. It is just a coincidence that lead people to conclude that everything in the body was made of those four fluids. Everything from here on out is based on the ancient understanding of the humors. You can’t get a medical degree with this dross.)
Blood came from the liver and gave rise to a sanguine personality, which made you optimistic, cheerful, sociable, and brave. It also made you impulsive and kept you from sticking to your projects and seeing things through. If you were an ancient Greek with ADHD, they would have drained your blood to fix it.
Yellow bile arose in the spleen and created a choleric temperament. It made you idealistic, passionate, and driven. But it also made aggressive and stubborn and easily angered. Hang out on any Internet forum and you’ll see choleric temperaments.
Black bile came from the gall bladder and leads to a melancholic personality. Melancholics were introverts and perfectionists. They also tended to be moody, sometimes even depressed. Their intense focus on things could also lead to tunnel vision.
Phlegm arose in the brain and lungs and lead to a phlegmatic temperament. Phlegmatic people were calm, rational, logical, and content. But they also tended to be lazy and inactive. They could be cool and difficult to relate to as well. Most people on the Internet want to think they are phlegmatic, but they lack the cool contentment and aren’t nearly as rational as they think they are.
Humoristic theory survived well into the 18th Century and it grew more and more complicated as time went on. Illnesses and personality problems were seen as imbalances of the humors. A complex list of correspondances between the humors and foods, drinks, herbs, times of day, times of year, and so forth developed. A choleric person might be treated by having wine at night, because those were associated with black bile which opposed choleric traits. For example.
In exterme cases, an excess of humor could be treated by removing excess fluid. Bloodletting was a commonly known practice, but inducing vomiting could reduce yellow bile and inducing diarhea was thought to relieve excess black bile. Cupping, the process of creating bruises with the use of heated cups, was thought to change the humor balance as well.
Meanwhile, it might be fun to get one of those personality correspondance charts and ask PCs in your game to choose a trait for their character. Maybe Gorgok the Barbarian is quite choleric while Astaria the Mage is very phlegmatic. You could use that for NPCs too.