Solar terms embody Chinese ecological wisdom
A painting dubbed the 18th of the 24 Solar Terms, Frost’s Descent, by Zhou Shenghua (1948–2000), a contemporary Chinese artist Photo: HEILONGJIANG ART MUSEUM
The 24 solar terms are a time system of the Chinese lunar calendar that is calculated by dividing the tropical year evenly into 24 periods. The name of each solar term matches a particular astronomical event or signifies some natural phenomenon. Over time, the concept of 24 solar terms has been widely adopted in China as well as by its neighboring countries. It epitomizes the ecological wisdom of the ancient Chinese—“follow nature.”
“Follow nature” suggests that people should act in accordance with natural laws, adjust ways of living to the times and make use of natural resources. According to the Huangdi Neijing (Yellow Emperor’s Canon of Medicine), the earliest extant medical canon in China, “[The changes of] Yin and Yang in the four seasons are the roots of all the things [in nature]. So the sages cultivate Yang in spring and summer while nourishing Yin in autumn and winter in order to follow such roots (the changes of Yin and Yang in different seasons). Violation of these roots means destruction of the Ben (primordial base) and impairment of the body. Thus the [changes of] Yin and Yang in the four seasons are [responsible for] the growth, decline and death of all things. Violation of it brings about disasters while abidance by it prevents the occurrence of diseases. This is what it means to follow the Dao (law of nature).”
Foundation of “follow nature”
The idea of “follow nature,” which is the core principle of the 24 solar terms, takes root in the long-term exploration of the relationship between human and nature.
The understanding of natural laws plays a crucial part in shaping this idea. Changing seasons is a natural phenomenon. When people gradually noticed the periodicity of changing seasons, variations of which cause animals to undergo hibernation or to migrate and plants to be dormant, they realized the importance of adjusting ways of living according to the periodic changes of nature.
The idea “follow nature” was also closely linked with the traditional Chinese philosophy, Tian Ren He Yi (literally known as “Heaven and man are an integral whole”). There are various interpretations of this principle, but it is commonly accepted that this philosophy encourages people to be in constant pursuit of harmony with nature. The concept of Tian Ren He Yi regards the natural forces as the supreme principle governing the universe and human society, while human beings still have the capacity to make choices and to impose those choices on the world. It stresses a harmonious relationship between humans and nature, in which human beings should respect their environments and make proper use of natural resources. The I Ching states, “Heaven and Earth in communion symbolize harmony. Likewise, the king makes appropriate adjustments to assist easy communion between Heaven and Earth and contribute to the harmonious reproduction of all things of creation so that all people under Heaven are blessed” (trans. Fu Huisheng).
Cosmology in ancient China played a part in the development of the idea of Tian Ren He Yi. The ancient Chinese perceived the universe as an organic whole and everything in the universe as being connected. Yin, Yang and Wuxing (Five Phases: water, fire, wood, metal and earth) are the core concepts of traditional Chinese cosmology. They believed that the passage of time is caused by the interaction between Yin and Yang. According to the ancient philosophical text Guanzi, “Spring, summer, autumn and winter are the evolvement of the Yin and Yang. The length of the daytime is the cooperative function of the Yin and Yang. The daytime and nighttime appearing in turns is the change of the Yin and Yang” (trans. Zhai Jiangyue). This means that Yin and Yang in balance represent the universe in an ideal condition. Therefore, human beings should adjust their ways of life according to the principles of Yin and Yang to achieve balance between these two fundamental forces.
Solar terms and Yueling
Based on respect for nature, the pursuit of harmony between nature and human beings, and traditional cosmology, ancient Chinese thinkers created a calendar in which a specific time matched a particular astronomical event or signified some natural phenomenon. The astronomical occurrences, the phenology of nature and the work of farmers during each month of the year are clearly described in early texts such as the Yueling (Proceedings of Government in the Different Months, a chapter of the Confucian classic, Liji). The proceedings of government in every month are divided into eight categories. The first category is about time. For example, “In the first month of spring the sun is in Shi (Shi is one of the Twenty-Eight Mansions; ancient Chinese astronomers divided the sky ecliptic into four regions, each region containing seven mansions, making a total of 28 mansions), the star culminating at dusk being Shen (a mansion of the sky ecliptic), and that culminating at dawn Wei (another mansion). Its days are jia and yi (“jia and yi” are the names of the days). Its divine ruler is Dai Hao, and the [attending] spirit is Gou-mang. Its creatures are the scaly……Its number is eight; its take (taste) is sour; its smell is rank (unpleasant). Its sacrifice is that at the door, and of the parts of the victim the spleen has the foremost place” (trans. James Legge).
The second category is about the weather and natural phenomenon of the first month of spring, as is recorded in the Yueling, “The east winds resolve the cold. Creatures that have been torpid during the winter begin to move. The fishes rise up to the ice. Otters sacrifice fish. The wild geese make their appearances.” What the son of Heaven should do during that month is clarified in the third category. The fourth category states the solar terms in that month and the related ritual ceremonies while the fifth category mentions other important ritual practices. The necessary practices, taboos and the results of violating taboos are specified in the last three categories respectively.
Clearly, the Yueling is based on the traditional belief, “follow nature.” For instance, since spring is the time of renewal and growth of all creatures, the Yueling tells people “not to use any female victims” as sacrifices to hills and forests. “Prohibitions are issued against cutting down trees. Nests should not be thrown down; unformed insects should not be killed, nor creatures in the Womb, nor very young creatures, nor birds just taking to the wing, nor fawns, nor should eggs be destroyed.”
Because the solar terms reflect the changes of the seasons, climate and phenology, they are important instructions for agricultural production as well as people’s daily lives. As the old saying goes, “When spring’s thunder cracks the sky in Jingzhe (Awakening of Insects, the 3rd of the 24 solar terms), it is time for farmers to engage in the busiest time for agricultural work.” Solar terms not only govern agricultural arrangements in ancient China and certain functions today, but also affect the regimen of the Chinese people. There are various old sayings telling people how to stay healthy or improve their health, such as “Wear more clothes during Bailu (White Dews, the 15th of the 24 solar terms) period and do not go swimming as autumn has come.” The essence of the traditional Chinese regimen lies in the belief that diet, clothing, housing and other aspects of human lives should coordinate with seasonal change.
Zhang Bo is a research fellow from the Research Institute of Beijing Studies at Beijing Union University.
edited by REN GUANHONG