Yin and yang arethoughtto arise together from an initial quiescence or emptiness (wuji, sometimes symbolized by an empty circle), and to continue moving in tandem untilquiescenceis reached again. For instance, dropping a stone in a calm pool of water will simultaneously raise waves and lower troughs between them, and this alternation of high and low points in the water will radiate outward until the movement dissipates and the pool is calm once more. Yin–yang, thus, always has the following characteristic: yin and yang describe opposing qualities in phenomena. For instance, winter is yin to summer's yang over the course of a year, and femininity is yin to masculinity's yang in human relationships.
It is impossible to talk about yin or yang without some reference to the opposite: yin–yang are rooted together. Since yin and yang are created together in a single movement, they are bound together as parts of a mutual whole. A race with only men or only women would disappear in a single generation; but men and women together create new generations that allow the race they mutually create (and mutually come from) to survive. The interaction of the two gives birth to things. Yin and yang transform each other: like an undertow in the ocean, every advance is complemented by a retreat, and every rise transforms into a fall. Thus, a seed will sprout from the earth and grow upwards towards the sky – an intrinsically yang movement. Then when it reaches its full potential height it will fall.

external image yin_yang.jpg

Symbolism and its significance

The relationship between yin and yang is often described in terms of sunlight playing over a mountain and in the valley. Yin (literally the 'shady place' or 'north slope') is the dark area occluded by the mountain's bulk, while yang (literally the 'sunny place' or 'south slope') is the brightly lit portion. As the sun moves across the sky, yin and yang gradually trade places with each other, revealing what was obscured and obscuring what was revealed. Yin is usually characterized as slow, soft, insubstantial, diffuse, cold, wet, and tranquil. It is generally associated with thefeminine, birth and generation, and with the night. Yang, by contrast, is characterized as fast, hard, solid, dry, focused, hot, and aggressive. It is associated withmasculinityand daytime.

I Ching

In theI Ching, yin yang are represented by broken and solid lines: yang is solid and yin is broken. These are then combined into trigrams, which are more yang or more yin depending on the number of broken and solid lines (e.g.is heavily yang, whileis heavily yin), and trigrams are combined into hexagrams. The relative positions and numbers of yin and yang lines within the trigrams determines the meaning of that trigram, and in hexagrams the upper trigram is considered yang with respect to the lower trigram, allowing complex depictions of interrelations.

Taijitu

The principle of yin and yang is represented in Taoism by the Taijitu(literally "diagram of the supreme ultimate") diagram. The term is commonly used to mean the simple 'divided circle' form, but may refer to any of several schematic diagrams representing these principles. Similar symbols have also appeared in other cultures, such as inCeltic artand Roman shield markings.

Religious and Philosphical

The yin-yang symbol and concept of the Zhou period reach into family and gender relations. Yin is female and yang is male. They fit together as two parts of a whole.