For about 2000 years medicine in Europe and the Middle East was dominated by humorism, which is the theory of four humors (and isn’t funny at all). The dominant version held that the human body contained four humors, or fluids, that determined characteristics of health and temperament. When these humors were in proper proportion the body and emotions were healthy, but all kinds of physical and mental illnesses were caused by humors getting out of wack. Although the theory of humorism was disproven in 1858, the preceding two millenia gave the concepts enough time to make an impact on the English language. These humors are blood, yellow bile, black bile, and phlegm. Let’s take a look at how each of them has seeped into the language.
blood - An ancient word from all the way back in Old English, blood is not the word Greek and Latin doctors and philosophers were using. The word in Latin is sanguis, which gives us sanguine, meaning “cheerful, hopeful, confident,” because that was the temperament associated with an excess of the humor blood. (In Greek this humor was haima, which gives us tons of medical words such as hemorrhage, hemoglobin, and anemia, but I can’t think of any that are specifically related to the theory of humorism.) Blood was thought to be hot and wet in nature, so a cold-blooded person who lacked the emotions that should be associated with blood was clearly unnatural. On the other hand, the French person with sang-froid , who also has cold blood, is considered admirable. That might be because in French sang meaning “blood” is a homophone with sens meaning “sense” (and it was often spelled that way in the 17th century), which may have affected the connotations of the phrase into someone who keeps a cool head.
yellow bile - Bile comes from Latin by way of French, reaching English in the 1660s. Yellow bile was hot and dry, and associated with a personality that was short-tempered, bitter, and angry. That’s why bile can mean “anger and bitterness” when people spew bile, and why a bilious disposition is peevish. Moreover, the Old English word for bile is gall, which is why having a lot of gall originally also meant bitterness or anger. (The sense of “impudence” is more recent, from about 1882.) Gall may also be the origin of felon, from Latin, as one who has a lot of gall, or bitterness. In Greek the humor was xanthe chole, from which we get choleric, meaning “easily angered, hot-tempered” (ca. 1580). It’s also the root of the disease cholera, thought to be caused by an excess of yellow bile. Speaking of yellow, we get the word jaundice from Old French for “yellow.” The condition of jaundice is actually caused by the yellowish pigments of bile, but the theory of four humors is why looking at something with a jaundiced eye means an attitude of bitterness and hostility.
black bile - Of course this also includes the word “bile,” but in English the metaphoric senses of bile mostly seem to refer to the angry yellow variety. In Greek, black bile is melaina chole, and you can probably see right away that this gives us (by way of Latin and Old French) melancholy, which is the temperament associated with this cold dry humor. The spleen was believed to be the source of black bile, and thus the source of melancholy and gloom. However, this bile word, too, has shifted toward the peevishness of yellow bile, and nowadays if someone “vents their spleen” the implication is anger more than depression.
phlegm - Medically speaking, the humor phlegm is not the same as the modern medical definition of phlegm, but the metaphoric uses come straight from the humor. A phlegmatic person is calm, lethargic, and apathetic. Our word phlegm is from Greek by way of Old French, and it comes from phlegein “to burn,” which is odd, since according to humorism phlegm is cold and wet.
humor - This word entered English in the 14th century, originally meaning “fluid or juice of an animal or plant.” (This moistness is related to humid.) It was the theory of humorism that extended the meaning from “fluid” to “mood, state of mind” by around 1520. The meaning “funniness, amusing quality” arrived around 1560 and probably came from the sense of “whim, caprice, brief state of mind” which may also be where we get the verb humor meaning “indulge a whim” (around 1580). (And by the way, the H was originally silent in English.)
temperament - The four humors are also often called the four temperaments, from the Latin word for “proper mixture, in correct proportion.” In other words, your temperament is your mixture of humors. This comes from the older verb temper “to mix in proper proportions,” from which we also get the noun temper meaning a specifically choleric state of mind (a bad temper) around 1825.
One other word I came across that English got from humorism is repercussion. Literally meaning “the act of driving back,” it appeared in English in the early 15th century referring to a medical treatment intended to drive back excess humors. The metaphoric sense came later.
If you want to go all the way back to Proto-Indo-European, the root *ghel- meaning “to shine” plus “yellow and green colors” is the ultimate root of many of today’s other words including choler, gall, jaundice, and yellow itself. Meanwhile, another PIE root *bhel-, which also meant “to shine” led to phlegm (because of the “burning” definition in Greek) and black (being the color of things that have been burned.)
For today’s illustrations I’ve got five sets of temperaments, which I’ve arranged by humor so you can compare how they’re portrayed. Sanguine often includes music, goats, and wine. Choleric includes swords, lions, and fire. Melancholy is usually portrayed with the head down or resting on the hand, along with miserliness (moneybags) and often tools of scholarship such as books or geometry instruments. And phlegmatic often includes turtles and water.
From Hippocrates to Ben Johnson and beyond, the idea of the four humors and their effect on people’s personalities and behaviors was a firm fixture of both science and popular culture. References to the humors and their effects abound in art, literature, and medicine, and recognizing them will help you understand a lot. As for today, I hope you’re able to stay in a good humor.
[Pictures: Four Humors, wood block prints from Minerva Britanna by Henry Peacham, 1612 (Images from Internet Archive);
Four Humors, hand colored woodcuts from German Calendar, 1498 (Images from National Library of Medicine);
Four Humors, wood block prints from Iconologia by Cesare Ripa, 1603 (Images from Universitätsbibliothek Heidelberg);
Four Temperaments, series of 4 engravings by Virgil Solis after Georg Pencz, 1530-62 (Images from The British Museum) ;
Four Humors, hand colored woodcuts pasted into a scrapbook by Gallus Kemli, 15th century (Image from Zentralbibliothek Zürich).]
