|Blood||spring||air||liver||warm & moist||courageous, hopeful, amorous|
|Yellow bile||summer||fire||gall bladder||warm & dry||easily angered, bad tempered|
|Black bile||autumn||earth||spleen||cold & dry||despondent, sleepless, irritable|
|Phlegm||winter||water||brain/lungs||cold & moist||calm, unemotional|
This is the origin of such practices as “bleeding” a patient; if someone was thought to have too much blood (their blood humor being out of balance), by removing excess blood, health could be restored.
This could be used as the basis of a healing system in an RPG, of course. Characters could have points for each humor, and diseases or other illnesses would cause one or more of them to be out of alignment. Spells could affect specific humors, with specific results; four different types of “cure disease” spell, for example. And, of course, if magical healing is not available, a chiurgeon would use humorism as the basis for his diagnosis and treatment.
If nothing else, humorism can provide some interesting background for your medieval-themed campaign.