An important feature of the ancient Chinese philosophy/theory about the universe is that the universe has to be conceived as a conglomerate of paired opposites. This point of view is also found in many other cultures and religions. For example in the Jewish Kabbalah, where it is called the basic law that governs everything in the universe. *

In order to be able to apply this 'law of paired opposites' in daily life, the terms Yin and Yang have traditionally been used in China:

    "The pairing of yin and yang makes up the great Leitmotiv, which penetrates all Chinese culture, and has defined all the characteristics of the traditional Chinese way of life." "Life," says Chuang Tzu, "is the harmonious blend of Yin and Yang." *

In the ancient Chinese philosophy / theory about the universe, all paired opposites of the universe are thus symbolized by Yin and Yang. And since it is very important in the perspective of my book, that the reader knows that these terms can be interpreted in different ways, I will explain this with the help of the Chinese characters by which the (philosophical) concepts Yin and Yang were and still are written:

or in printed form: 陰  陽

Contrary to what many people believe, Chinese characters are not a chaotic collection of lines, but are composed according to fixed rules. Each character consists of one or more parts. Each part (building block) is a figure or a pattern of lines. Many of these figures go back to icons that represent a concept. Therefore they also implied a sound, a syllable to be exact, namely the word that the term indicated. This made it possible to compose characters according to the 'rebus principle': one or more parts of the character tell us something about the meaning, or the category of meanings, of the character, other parts say something about the pronunciation, the sound of the word.

The concrete meaning of the parts 侌 and 昜 is "dark" and "light". A simple and clear contrast; a paired oppposite, so to speak, and they are pronounced as yīn and yáng in contemporary Mandarin. In this way the words yīn and yáng were used by the ancient Chinese philosophers as a metaphor for both sides of a paired opposite. In order to make a distinction in writing between their concrete and their philosophical meanings, the characters for yīn = dark and yáng = slightly were expanded with an extra symbol on the left:⻖.

The symbol ⻖ is a more modern simplified form of 阜 and traditionally has two meanings in Chinese: "much, abundant" as an adjective and "mound, dam, hill" as a noun; so two homonyms, cf. english "bear" in  "he was attacked by a brown bear" and "I can't bear being bored". The Confucianists are supporters of the first meaning, while the Daoists use the second one. According to the Daoists, the meaning of the philosophical characters of Yin and Yang is "shadow side" resp. "Sunny side"; the 'building block' 阜 is a kind of anchoring point, while 侌 (yīn) and 昜 (yáng) show two complementary aspects of one and the same thing. The Confucianists, however, state that 阜 must be read as 'full of'. The meaning of the characters 陰 and 陽 is in this case 'full of dark' or 'full of light'. This way, the two characters respectively mean the Great Yin and the Great Yang, making them consistent with the Creation story of the Confucianists, which is not the case for the 'hill interpretation' adhered to by Daoism.

Confucianism considers the Great Yin and the Great Yang as the two polar primal forces that form the basis for all paired opposites in the world*, while Daoism sees them as the proverbial two sides of a coin. And because the Confucianists have been dominant in China over the centuries, their interpretation of the characters is the most well known.

The Great Yin and the Great Yang may be regarded as a metaphor for all paired opposites in the world, but only in a special way. This is represented by Confucianists with the dynamic symbol (Yin is black and Yang is white). The dynamic symbol makes it particularly clear that, according to the Confucianist version, paired opposites are opposed on the basis of a changing, inner domination of either Yin or Yang. This also applies to night and day: A night that is Yin can have many light points that are Yang, and a day that is yang can also have its shadow that ...

The association of random natural phenomena with Yin and Yang is therefore always relative: Nights can also be Yang, for example in the case of a full moon or of northern lights, and so can days be Yin when they are too cold or too dark.
This also implies that:

• The term Yin is used for natural phenomena where cold dominates, such as inertia, night, shadow, dark color, massiveness, feminine and so on
• The term Yang is used for natural phenomena in which warmth dominates, like activity, day, sunny, light color, spatial, male, and so on.
  

This form of associating is called the Yin / Yang dialectics. Its existence is in accordance with the fact that the Great Yin and the Great Yang are not only the basic forms of Yin and Yang, but also of six intermediate or combined forms of the two. This relation is represented in the Yijing by means of eight trigrams: ☰, ☱, ☲, ☳, ☴, ☵, ☶, ☷, with the explanation that they are as mother Yin ☷ and father Yang ☰ with their six children, three of which are more Yang and three more Yin.* There are two arrangements of these eight trigrams (八卦). The arrangement of the Primordial Heaven (先天), "Earlier Heaven" or "Earlier world" and the one of the Manifested Heaven (後天), "Later Heaven" or "inner world" (see respectively Left and Right in the picture below),"*

The hill interpretation of Yin and Yang can be found in the Shuowen jiezi (說文解字) by Xu Shen (許慎), and is also mentioned by the well-known Dutch sinologist and Daoist Kristofer Schipper in his book: TAO, De levende religie van China.* The Theory of the Elements is also based on the hill interpretation. More on that in the next section.

 Continue to: Basic rhythms of the universe