The spleen belongs to earth and has the functions of movement and transformation and of controlling the blood. It governs the flesh, opens at the mouth, and has drool as its humor. It stores ideation, its mind is thought, and its voice is singing. It stands in exterior-interior relationship with the stomach. It holds the Office of the Granaries.

Earth

All the food we eat comes directly from crops grown in the earth or from animals feeding on vegetation growing from the earth. Salt, our main mineral food additive, comes from the earth too. Hence, earth is the mother of the myriad living things (万物之母 wàn wù zhī mǔ), living things here referring to all forms of life.

Afternoon, center: Afternoon is the part of the day that follows noon. It is associated with the central position. Unlike the positions of the other four phases, the center is not related to the position of the sun. The earth-center pairing probably arose when the heart, rather than the spleen, was associated with earth in an earlier pairing of the viscera to the phases.

Late summer, transformation: The Chinese, as we do, normally speak of four seasons, not five. However, with the development of the five-phase doctrine, the year had to be divided into five. For this reason, late summer (长夏 cháng xià) was inserted between summer and autumn, the turning point between yáng and yīn parts of the year. Late summer, which in the yearly cycle corresponds to afternoon in the daily cycle, was chosen as the fifth season because it is a time very important in human agriculture when staple crops ripen and become edible. The activity of nature at this time is summed up as transformation (化 huà).

The exact definition of this season is the subject of disagreement, but Wáng Bīng, the renowned commentator of the Nèi Jīng, said that it is the last month of summer, the sixth month of the lunar calendar, corresponding to the end of July and beginning of August in our calendar.

Earth is the sowing and reaping (土爰稼穑 tǔ yuán jià sè): Although sowing and reaping are two separate activities, neither of which is associated with late summer, the combination of the two simply means the work of producing food out of the earth, that is, agriculture.

Yellow is the color associated with earth. The Chinese 黄 huáng covers a wider range of colors than the English yellow, notably including light brown. Brown-haired dogs, tan-colored shoes, and normal-colored feces are described as 黄. So, yellow is the color of earth, especially the earth in the Yellow River region, which is paler than the deep brown of other climes. It is also the color of staple crops as they ripen. Although yellow is the color of grasses in other seasons of the year, late summer is the coming of yellow.

It might be noted in passing that yellow came to be associated with royalty in Zhōu Dynasty. The ruler was naturally associated with the central position, which corresponded to earth among the five phases. In the early pairing between the five viscera and the five phases, earth was associated with the heart. Only in the later pairing, which still applies to this day, was the ruler associated with the heart, and hence with fire and the color red. Thus imperial yellow is hangover from older associations.

Sweetness is the flavor of grains and fruits as they become ready for harvesting. Sweet foods build qì and blood, and in fact, sweetness is a common property of all supplementing medicinals.

Five-phase cycles: In the engendering cycle, earth engenders metal, as earth produces metal ores. Earth is engendered by fire, since natural vegetation needs to be burned to open up farmland, and stubble is burned to enrich the earth each year. In the restraining cycle, earth restrains water, as it restricts the flow of rivers. Earth is restrained by wood because it can be moved by wooden implements.

The Spleen

Without microscopy and biochemistry, the spleen reveals nothing of its functions to the naked senses. However, according to the knowledge of organs gained through yīn-yáng theory, it is a solid rather than a hollow organ, and so was presumed to be a storehouse for precious substances, rather than a dispatch house for passing on food or waste. It was undoubtedly designated as such by its proximity to the stomach, which, from gross dissection, is clearly identifiable as a collecting place for ingested food, that is, a dispatch house. As a solid organ lying adjacent to the stomach, the spleen was considered the stomach’s corresponding storehouse, where the nutrients of food, or as they were called, the essence of grain and water, begin their journey as the raw material to produce qì and blood. Thus, although the spleen is now known to be a lymphatic and blood-filtering organ, it was rationally, though erroneously, identified by early Chinese medical scholars as the organ responsible for extracting nutrients from the stomach to make qì and blood. With this, it becomes obvious why the spleen was assigned to the earth phase. As the earth produces food for our sustenance, so the spleen produces the essence that is eventually transformed into qì and blood. Once this mistake about the function of the spleen is understood, the Chinese medical conception of this organ becomes clear.

Scholars believe that the spleen was added to the other four viscera under the influence of the systems of correspondence, which required a bowel and a viscus to be paired with each phase. Previously, the stomach had been considered the main organ of digestion. In the Nèi Jīng, a pulse that reflects the health of the digestive system is described as one that has stomach. The notion of the stomach as the main digestive organ survived in the work of Zhāng Jī (Zhāng Zhòng-Jǐng), where the digestive system is referred to as the stomach domain.

The spleen governs movement and transformation: The spleen moves the contents of the stomach to promote digestion and extracts the the essence of grain and water (nutrients). It then sends these upward to the heart and lung. By processes poorly explained, the nutrients are converted into qì, blood, and bodily fluids. The upward movement of spleen qì evinces a yīn-yáng contrast with the downward movement of stomach qì. The spleen is a yīn organ whose qì is characterized by yáng upward movement, while the stomach is a yáng organ whose qì is characterized by yīn downward movement.

The spleen is the root of later heaven: The term later heaven refers to the acquired constitution. This statement derives directly from the spleen’s being the source of qì and blood formation, which determines the acquired constitution of an individual.

The spleen controls the blood means that the spleen can prevent bleeding. Spontaneous bleeding, such as nosebleed, bloody stool, or bleeding via the vagina (called flooding and spotting in Chinese medicine), is attributed to heat causing blood to burst out of the vessels (frenetic movement of hot blood), to static blood obstructing the vessels, or to qì failing to contain the blood. The latter disorder is caused by insufficiency of qì, which can be traced to the spleen failing to produce adequate supplies of qì. It is therefore treated by supplementing the spleen to boost qì. The function of controlling the blood was therefore inferred from the direct observation of bleeding in patients who do not absorb nutrients properly.

The spleen governs the flesh: The spleen’s relationship to the flesh is equally obvious, since if we do not eat we become thin, if we eat too much, we become fat, and if we have a poorly functioning digestive system, we may become either thin or overweight and experience fatigue and lack of strength. Since fatigue and lack of strength are felt mostly in the limbs, it is also said that the spleen governs the four limbs. From an anatomical perspective, the notion of flesh overlaps with that of the sinews, as previously discussed under Liver, Wood, Office of General above.

The spleen opens at the mouth: The relationship of the spleen to the mouth is obvious too, since all ingested food passes through the mouth. By extension, the spleen and the stomach control the appetite.

The spleen has its bloom in the lips and the four whites: The health of the spleen is reflected in the state of the fleshiness, color, and moistness of the lips and the surrounding area, referred to as the four whites. This derives from the spleen’s association with the mouth and from direct correlation between the observed state of the lips and the health of the digestive system.

Drool is the humor of the spleen: Drool (涎 xián), which is one of two kinds of saliva posited in Chinese medicine, is naturally also associated with the spleen. Drool wells in the mouth at the sight of food, and drooling is observed in infants who have digestive tract worms. The other kind of saliva is spittle, which is associated with the kidney. More at spittle is the humor of the kidney under Kidney, Water, Office of Forceful Action below.

The spleen stores ideation (脾藏意 pí cáng yì). Ideation is our ability to produce new thoughts, ideas, explanations, plans, and intentions; in other words, the creative aspect of our minds. This is directly related to the association of earth with productiveness; earth is the mother of the myriad living things, including ideas produced by our minds.

Thought is the mind of the spleen. Thought or pensiveness (思 sī) is a state of mind rather than an emotion. Unlike emotions, it is not attended by bodily sensations. Its pairing with the spleen was undoubtedly prompted only by the association with the productivity of spleen-earth, in the same way as ideation.

Excessive thinking or rumination can damage the function of the spleen, just as over-cultivation of farmland taxes the earth. This affects the production of qì and blood, giving rise to a vacuity pattern.

Singing is the voice of the spleen: This association presumably derives from the notion of song as a creative use of the voice.

The spleen is averse to dampness: It is susceptible to externally contracted dampness, as well as to dampness arising in the body when spleen qì is weak and fails to conduct water-damp (water and dampness) out through the digestive tract. Whatever the cause, dampness manifests in fullness and distension of the stomach duct and abdomen, sloppy stool, sensations of generalized heaviness, and a thick moist white, possibly slimy tongue fur. Just as farmland will not produce maximum yields if it is not well-drained, so a spleen clogged by dampness will produce poor yields of qì and blood.

The spleen is the source of phlegm formation (脾为生痰之源 pí wéi shēng tán zhī yuán) refers to the notion that dampness can concentrate to form phlegm. This happens when splenic movement and transformation is too weak to eliminate dampness. Sometimes other factors are involved. For example, qì stagnation hampers the movement of water-damp, causing it to gather and concentrate, while heat boils the fluids into a thicker form. Despite these other factors, phlegm is understood to originate in the spleen because it is a thicker form of bodily fluids derived by the spleen from liquid in the digestive tract.

Office of the Granaries

The spleen and stomach hold the Office of the Granaries; the five flavors arise from it. The office of the granaries is comparable to the department or ministry of agriculture, ensuring sustenance for the people. It is the governmental counterpart of earth in nature.

The inclusion of the stomach in the above phrase is of interest. It may allude to a time when the stomach was considered the main digestive organ.

Summary of Spleen-Earth

The spleen belongs to earth and governs movement and transformation. It governs the flesh, opens at the mouth, and has its bloom in the lips and four whites. Its humor is drool, and its mind is thought. It holds the Office of the Granaries.

• The location on the underside of the stomach prompted the idea that the spleen was the storing organ corresponding to the stomach and hence an organ of digestion responsible for movement and transformation, helping the stomach to digest, extracting the essence of grain and water to produce qì and blood, and warming and transforming water-damp.
• The association with earth rests on the spleen’s being the source of qì and blood production, as earth provides sustenance for humans and animals.
• The flesh is associated with the spleen because it is marker of strength of digestion and assimilation. The mouth, lips, and drool are associated with the spleen they all directly related to digestion.
• Ideation and thought derive from the productiveness of earth. Excessive thought damages the spleen is like the over-intensive use of soil. Singing is the creative use of the voice.
• The Office of the Granaries, securing food supplies for the nation, naturally corresponds to earth in nature.