Yin and Yang in Equal Measure: The Way of Central Harmony and the Equilibrium of Day and Night at the Spring Equinox
This article offers a multi-dimensional exploration of the Spring Equinox (Chunfen) among the Twenty-Four Solar Terms, drawing on pre-Qin Confucian and Daoist philosophy, the original meanings of Chinese characters, and astronomical phenomena. By analyzing the character 'fen' (divide/equalize), the sun's alignment with the equator, and seasonal signs such as the return of swallows and the onset of thunder, it reveals the profound wisdom of 'central harmony' and the unity of Heaven and humanity embedded in the equinox's equal days and nights.
Chapter Six: The Daoist Perspective -- Guarding the Center, the Blending of Qi, and the Way of Harmony
I. "Too Many Words hasten exhaustion; better to guard the center"
If the Confucians expounded the spirit of the Spring Equinox through "attaining central harmony," the Daoists, through "guarding the center" (shouzhong) and "blending into harmony" (chonghe), offered another profound layer of interpretation.
The Most High (Laozi) states in Chapter Five of the Daodejing: "The space between Heaven and Earth -- is it not like a bellows$4 Empty yet inexhaustible; the more it moves, the more it brings forth. Too many words hasten exhaustion; better to guard the center."
The "guarding the center" here, though verbally similar to the Confucian "holding the center," differs subtly in meaning. The Confucian "holding the center" emphasizes grasping proper measure in human affairs -- an active moral practice. The Daoist "guarding the center" emphasizes maintaining an inner state of quiescence and luminous emptiness -- an inward spiritual cultivation. Zhong in the Most High's usage is both impartial equilibrium and the original state of quiescent emptiness.
Comparing "guarding the center" with the Spring Equinox yields a distinctive resonance. At the Spring Equinox, Heaven and Earth rest in the equilibrium of yin and yang in equal halves -- this equilibrium is precisely a state of "guarding the center." Heaven and Earth incline neither toward yang (as at the Summer Solstice) nor toward yin (as at the Winter Solstice), but hold to the impartial midpoint. The Most High says "Too many words hasten exhaustion; better to guard the center," reminding us not to fall into excessive action and noise, but to return to the original source of quiescent equilibrium. Heaven and Earth at the Spring Equinox provide the most natural model for this "guarding the center" -- quietly presenting the equilibrium of yin and yang, neither exalted nor abased, impartial and unbiased, the highest state of "guarding the center."
II. "Blending Qi into Harmony": The Mystery of Yin-Yang Union
The Daoist understanding of "harmony" is concentrated in the Most High's famous statement. Daodejing, Chapter Forty-Two: "The Way gives birth to one; one gives birth to two; two gives birth to three; three gives birth to the myriad things. The myriad things carry yin on their backs and embrace yang in their arms, and through the blending of qi (chongqi) achieve harmony."
This passage is the core of Daoist cosmogony and a key to understanding the Spring Equinox's "yin and yang in equal halves." "The Way gives birth to one; one gives birth to two; two gives birth to three; three gives birth to the myriad things" -- the Way is the origin of all things; from the Way arises "one" (primordial, undifferentiated qi); from one comes "two" (the two qi of yin and yang); from the mutual interaction of the two qi arises "three" (yin, yang, and the harmony of their union); and from this the myriad things are generated.
Most crucial are the last two lines: "The myriad things carry yin on their backs and embrace yang in their arms, and through the blending of qi achieve harmony." All things bear yin and embrace yang, and through the surging intermingling of the two qi ("blending qi") attain harmony. This reveals a profound truth: the generation and existence of all things depends not on yang alone, nor on yin alone, but on the "blending" (surging intermingling) of the two qi -- the "harmony" that results. Pure yang does not generate; pure yin does not grow; only when yin and yang interact and blend into unity can they transform and nourish the myriad things.
The Spring Equinox is precisely the exemplary moment of the two qi of yin and yang "blending into harmony"! At the equinox, yin and yang are in equal halves, the two forces evenly matched, engaged in the most thorough intermingling. This is neither pure yang (the Summer Solstice is yet to come) nor pure yin (the Winter Solstice is past), but the equilibrium of yin and yang "blending into harmony." It is precisely under this state of yin-yang union that all things flourish -- swallows return, vegetation sprouts, hibernating creatures revive, every one a result of yin and yang "blending into harmony."
The Most High's insight of "blending qi into harmony" provides the most profound philosophical explanation for the Spring Equinox's "yin and yang in equal halves": the Spring Equinox is precious not only for its "equality" (yin and yang being equal) but for the "harmony" that this equality engenders (yin and yang uniting to generate all things). Equality is the condition for harmony; harmony is the result of equality.
III. "Guarding the Center," "Blending into Harmony," and "Knowing Harmony Is Called Constancy"
The Most High also says in Daodejing, Chapter Fifty-Five: "Knowing harmony is called constancy; knowing constancy is called illumination."
Here, "harmony" is elevated to the status of "constancy" (chang -- the eternal pattern). Why is "harmony" "constancy"$5 Because the continued existence of all things in Heaven and Earth fundamentally depends on the harmony of yin and yang. Once yin and yang lose their harmony -- if yang is too dominant, all things parch and wither; if yin is too dominant, all things freeze and die -- the normal operation of Heaven and Earth is disrupted. Only in yin-yang harmony can the four seasons alternate in proper order and all things flourish without ceasing. Therefore, "harmony" is the "constancy" of Heaven and Earth, the eternal law of cosmic operation.
The Spring Equinox is precisely the moment when Heaven and Earth display their "harmony" as "constancy." On this day, yin and yang are in equal halves, blending into unity, and Heaven and Earth present their most harmonious state. One who "knows harmony as constancy," observing the equilibrium of Heaven and Earth and experiencing the blending of yin and yang at the Spring Equinox, can apprehend the eternal law pervading the cosmos -- "harmony." And apprehending "harmony" is "knowing constancy"; knowing constancy is "illumination."
IV. Master Zhuang on Harmony: Harmony with Heaven, Harmony with Humanity
Master Zhuang's exposition of "harmony" goes a step further, distinguishing "harmony with Heaven" (tianhe) from "harmony with humanity" (renhe).
Zhuangzi, "Tiandao" ("The Way of Heaven"), states: "Those who clearly understand the virtue of Heaven and Earth -- they have grasped the great root and great ancestor; they are in harmony with Heaven. That by which they equalize and regulate all under Heaven -- they are in harmony with humanity. Harmony with humanity is called 'the joy of humanity'; harmony with Heaven is called 'the joy of Heaven.'"
This passage distinguishes two kinds of "harmony": harmony with the natural world of Heaven and Earth (harmony with Heaven), and harmony with society and human affairs (harmony with humanity). Notably, Master Zhuang uses "equalize and regulate all under Heaven" (juntiao tianxia) to describe "harmony with humanity" -- the character jun ("equalize") and the character tiao ("regulate") echo the Spring Equinox's calibration of weights and measures and its "equalizing the realm" governance.
Applying Master Zhuang's distinction between "harmony with Heaven" and "harmony with humanity" to the Spring Equinox, we can perceive the dual harmony it contains. The equinox's "equal days and nights, balanced cold and heat" is Heaven and Earth's own "harmony with Heaven" -- Heaven and Earth in their most harmonious equilibrium. The ancients' act of calibrating weights and measures on the Spring Equinox to "equalize and regulate the realm" was the emulation of heavenly harmony in pursuit of "harmony with humanity" -- using the equilibrium of the Way of Heaven to seek fairness in the human world. The ancients meant precisely to accomplish "harmony with humanity" at the very moment when "harmony with Heaven" was displayed. This act of emulation and transformation from "harmony with Heaven" to "harmony with humanity" is the most refined practice of the Chinese ideal of "the unity of Heaven and humanity."