The four humors
Humorism, or humoralism, is a now discredited (but historically important) theory of the makeup and workings of the human body, adopted by Ancient Greek and Roman physicians and philosophers, positing that an excess or deficiency of any of four distinct bodily fluids in a person directly influences their temperament and health. From Hippocrates onward, the humoral theory was adopted by Greek, Roman and Islamic physicians, and became the most commonly held view of the human body among European physicians until the advent of modern medical research in the nineteenth century.
The four humors of Hippocratic medicine are black bile (Gk. melan chole), yellow bile (Gk. chole), phlegm (Gk. phlegma), and blood (Gk. haima), and each corresponds to one of the traditional four temperaments. A humor is also referred to as a cambium (pl. cambia or cambiums).
Essentially, this theory holds that the human body was filled with four basic substances, called humors, which are in balance when a person is healthy. All diseases and disabilities supposedly resulted from an excess or deficit of one of these four humors. These deficits could be caused by vapors that were inhaled or absorbed by the body.
The four humors were black bile, yellow bile, phlegm, and blood. Greeks and Romans, and the later Muslim and Western European medical establishments that adopted and adapted classical medical philosophy, believed that each of these humors would wax and wane in the body, depending on diet and activity. When a patient was suffering from a surplus or imbalance of one fluid, then said patients’ personality and physical health would be affected. This theory was closely related to the theory of the four elements: earth, fire, water and air; earth predominantly present in the black bile, fire in the yellow bile, water in the phlegm, and all four elements present in the blood.
Paired qualities were associated with each humor and its season. The word humor is a translation of Greek χυμός, chymos (literally juice or sap, metaphorically flavor). At around the same time, ancient Indian Ayurveda medicine had developed a theory of three humors, which they linked with the five Hindu elements.
Although modern medical science has thoroughly discredited humorism, the theory dominated Western medical thinking for more than 2,000 years.
The concept of four humors may have origins in ancient Egypt or Mesopotamia, though it was not systemized until ancient Greek thinkers around 400 BC directly linked it with the popular theory of the four elements earth, fire, water and air (Empedocles).
Fåhræus (1921), a Swedish physician who devised the erythrocyte sedimentation rate, suggested that the four humours were based upon the observation of blood clotting in a transparent container. When blood is drawn in a glass container and left undisturbed for about an hour, four different layers can be seen. A dark clot forms at the bottom (the “black bile”). Above the clot is a layer of red blood cells (the “blood”). Above this is a whitish layer of white blood cells (the “phlegm”, now called the buffy coat). The top layer is clear yellow serum (the “yellow bile”).
The four temperaments (Clockwise from top right: choleric; melancholic; sanguine; phlegmatic).
Hippocrates is the one usually credited with applying this idea to medicine. Humoralism, or the doctrine of the four temperaments, as a medical theory retained its popularity for centuries largely through the influence of the writings of Galen (131–201 AD) and was decisively displaced only in 1858 by Rudolf Virchow’s newly published theories of cellular pathology. While Galen thought that humors were formed in the body, rather than ingested, he believed that different foods had varying potential to be acted upon by the body to produce different humors. Warm foods, for example, tended to produce yellow bile, while cold foods tended to produce phlegm. Seasons of the year, periods of life, geographic regions and occupations also influenced the nature of the humors formed.
The imbalance of humors, or dyscrasia, was thought to be the direct cause of all diseases. Health was associated with a balance of humors, or eucrasia. The qualities of the humors, in turn, influenced the nature of the diseases they caused. Yellow bile caused warm diseases and phlegm caused cold diseases.
In On the Temperaments, Galen further emphasized the importance of the qualities. An ideal temperament involved a balanced mixture of the four qualities. Galen identified four temperaments in which one of the qualities, warm, cold, moist or dry, predominated and four more in which a combination of two, warm and moist, warm and dry, cold and dry or cold and moist, dominated. These last four, named for the humors with which they were associated—that is, sanguine, choleric, melancholic and phlegmatic, eventually became better known than the others. While the term temperament came to refer just to psychological dispositions, Galen used it to refer to bodily dispositions, which determined a person’s susceptibility to particular diseases as well as behavioral and emotional inclinations.
In Islamic medicine, Avicenna (980–1037) repeated the ancient theory of four humours in The Canon of Medicine (1025):
From mixture of the four [humors] in different weights, [God the most high] created different organs; one with more blood like muscle, one with more black bile like bone, one with more phlegm like brain, and one with more yellow bile like lung.
[God the most high] created the souls from the softness of humors; each soul has it own weight and amalgamation. The generation and nourishment of proper soul takes place in the heart; it resides in the heart and arteries, and is transmitted from the heart to the organs through the arteries. At first, it [proper soul] enters the master organs such as the brain, liver or reproductive organs; from there it goes to other organs while the nature of the soul is being modified in each [of them]. As long as [the soul] is in the heart, it is quite warm, with the nature of fire, and the softness of bile is dominant. Then, that part which goes to the brain to keep it vital and functioning, becomes colder and wetter, and in its composition the serous softness and phlegm vapor dominate. That part, which enters the liver to keep its vitality and functions, becomes softer, warmer and sensibly wet, and in its composition the softness of air and vapor of blood dominate.
In general, there are four types of proper spirit: One is brutal spirit residing in the heart and it is the origin of all spirits.
Another – as physicians refer to it – is sensual spirit residing in the brain. The third – as physicians refer to it – is natural spirit residing in the liver. The fourth is generative – i.e. procreative – spirits residing in the gonads. These four spirits go-between the soul of absolute purity and the body of absolute impurity.
Influence and legacy
Typically “eighteenth-century” practices such as bleeding a sick person or applying hot cups to a person were, in fact, based on the humor theory of surpluses of fluids (blood and bile in those cases). Ben Jonson wrote humor plays, where types were based on their humoral complexion. Methods of treatment like bloodletting, emetics and purges were aimed at expelling a harmful surplus of a humor. Other methods used herbs and foods associated with a particular humor to counter symptoms of disease, for instance: people who had a fever and were sweating were considered hot and wet and therefore given substances associated with cold and dry. Paracelsus further developed the idea that beneficial medical substances could be found in herbs, minerals and various alchemical combinations thereof. These beliefs were the foundation of mainstream Western medicine well into the 1800s.
Central to the treatment of unbalanced humors was the use of herbs. Specific herbs were used to treat all ailments simple, common and complex etc, from a uncomplicated upper respiratory infection to the plague. For example, chamomile was used to decrease heat, and lower excessive bile humor. Also, arsenic was used in a poultice bag to ‘draw out’ the excess humor(s) that led to symptoms of the plague. Philip Moore, who wrote on the hope of health, and Edwards, who wrote Treatise concerning the Plague discuss how these herbs are helpful in curing physical disease. They also discuss the importance of maintaining an herb garden.
The Unani school of medicine, currently practiced in Perso-Arabic countries, and in India and Pakistan, is based on Galenic and Avicennian medicine in its emphasis on the four humors as a fundamental part of the methodologic paradigm.
There are still remnants of the theory of the four humors in the current medical language. For example, modern medicine refers to humoral immunity or humoral regulation when describing substances such as hormones and antibodies that circulate throughout the body. It also uses the term blood dyscrasia to refer to any blood disease or abnormality. The associated food classification survives in adjectives that are still used for food, as when some spices are described as “hot”, and some wines as “dry”. When the chili pepper was first introduced to Europe in the sixteenth century, dieticians disputed whether it was hot or cold.
Theophrastus and others developed a set of characters based on the humors. Those with too much blood were sanguine. Those with too much phlegm were phlegmatic. Those with too much yellow bile were choleric, and those with too much black bile were melancholic. The idea of human personality based on humors contributed to the character comedies of Menander and, later, Plautus. Through the neo-classical revival in Europe, the humor theory dominated medical practice, and the theory of humoral types made periodic appearances in drama.
Because people believed that the quantity of humors in the body could not be replenished, there were folk-medical beliefs that the loss of fluids was a form of death.
The humors can be found in Elizabethan works, such as in Taming of the Shrew, in which the character Petruchio pretends to be irritable and angry to show Katherina what it is like being around a disagreeable person. He yells at the servants for serving mutton, a “choleric” food, to two people who are already choleric.
Foods in Elizabethan times were all believed to have an affinity with one of these four humors. A person showing signs of phlegmatism might have been served wine (a choleric drink and the direct opposite humor to phlegmatic) to balance this.