This English version was translated from the Chinese original with AI assistance. The Chinese text is authoritative.
Chinese characters originate from the Book of Changes, so the construction of basic characters always comes in opposing pairs. For example: (日 rì, “sun” / 月 yuè, “moon”), (陽 (阳) yáng / 陰 (阴) yīn), (白 bái, “white” / 黑 hēi, “black”), (昼 zhòu, “daytime” / 夜 yè, “night”), (朝 zhāo, “morning” / 暮 mù, “dusk”), and so on.
The Zhouyi says: “In change there is the Supreme Ultimate, which gives birth to the Two Modes.” The sun and the moon are among the best representatives of yin and yang. The sun stands for yang, the moon for yin. 日 mainly denotes “the sun” and the time of one daytime, and it also means one full day and night. In the early forms of the character 日, it was mainly a circle with a dot in the middle. The sun is round, and roundness is an ultimate expression of yang; when yang reaches its extreme, yin is born, and the dot in the middle represents the yin that is born. The sun is the greatest yang thing in our lives, so it can be represented by a circle with a dot inside. By extension, the time when there is sun is one day; by further extension, a recurring interval of one day can also be expressed by 日.
Some people think this character 日 also expresses a view of the universe: the dot in the middle is the sun, with planets circling around it — that is, heliocentrism.
月 is the sign of yin. “一” (one) is yang, “二” (two) is yin. When the circle opens, the yang qi leaks out and the yin qi is born; producing the yin expressed by the “二” in the middle gives the character 月.
陽 (阳) is made from 阝, from 日 and from 月. 阝 represents a mountain; in 昜, the sun is above and the moon below, separated by a horizontal stroke in the middle — yin and yang divided in two — expressing the relationship of waxing and waning between yin and yang. The sun rises over the mountain and the moon sets, expressing a state in which yang has grown strong and yin has weakened.
陰 (阴) is made from the mountain, from 今 and from 云 (yún, “cloud”): clouds cover the sun — an overcast day. The original meaning of 今 is to murmur with one’s head bowed, a gloomy look; clouds covering the sunlight, a gloomy, overcast look — that is 陰 (阴).
A flick of a stroke above 日 makes 白. The flick expresses one property of the sun — whiteness. 黑: a compound-ideative character. In the small-seal form, the top is the ancient character 囱 (chimney), and the bottom is the character 炎 (fire), expressing the abundance of smoke from burning. Together they express being blackened by smoke and fire. Original meaning: black. Black and white are yin and yang to each other.
东 (東) is made from 日 and from 木 (mù, “tree”): the direction in which the sun rises through the trees is the east. 西 (xī, “west”) is the original form of 栖 (qī, “to roost”). Original meaning: the bird enters its nest to rest — 西. The sun sets below the horizon; the sound is the same as 息 (xī), to rest.
In 朝, the 日 on the left has a cross 十 above and below it, expressing the rays of the rising sun. Remove these two crosses and you get 明 (míng, “bright”): when the sun rises, all is bright — expressing the scene of the morning sun rising in the east.
昼: 尺 above and 旦 below; the sun is between a horizontal stroke and 尺, meaning the sun above the horizon traveling across the sky. 夜: a dot expresses the property of yin; below it is “一,” expressing a divided period of time; further below, a person beside the moon — the time when the moon is out; beneath the canopy of the sky, a person standing under the moon: the mood of night — that is 夜.
