- The meaning of Yin-Yang
  This Symbol (Yin-Yang) represents the ancient Chinese understanding of how things work. The outer circle represents "everything", while the black and white shapes within the circle represent the interaction of two energies, called "yin" (black) and "yang" (white), which cause everything to happen. They are not completely black or white, just as things in life are not completely black or white, and they cannot exist without each other.

While "yin" would be dark, passive, downward, cold, contracting, and weak, "yang" would be bright, active, upward, hot, expanding, and strong. The shape of the yin and yang sections of the symbol, actually gives you a sense of the continual movement of these two energies, yin to yang and yang to yin, causing everything to happen: just as things expand and contract, and temperature changes from hot to cold.

from Patricia Ebrey, Chinese Civilization : A Sourcebook, 2d ed. (New York: Free Press, 1993), pp. 77-79
[Ebrey Introduction] The concepts of Yin and Yang and the Five Agents provided the intellectual framework of much of Chinese scientific thinking especially in fields like biology and medicine The organs of the body were seen to be interrelated in the same sorts of ways as other natural phenomena, and best understood by looking for correlations and correspondences. Illness was seen as a disturbance in the balance of Yin and Yang or the Five Agents caused by emotions, heat or cold, or other influences. Therapy thus depended on accurate diagnosis of the source of the imbalance.

The earliest surviving medical texts are fragments of manuscript from early Han tombs. Besides general theory, these texts cover drugs, gymnastics, minor surgery, and magic spells. The text which was to become the main source of medical theory also apparently dates from the Han. It is the Yellow Emperor's Classic of Medicine, supposed to have been written during the third millennium BCE by the mythical Yellow Emperor. A small portion of it is given below.

The Yellow Emperor said ''The principle of Yin and Yang is the foundation of the entire universe. It underlies everything in creation. It brings about the development of parenthood; it is the root and source of life and death it is found with the temples of the gods In order to treat and cure diseases one must search for their origins.

"Heaven was created by the concentration of Yang, the force of light, earth was created by the concentration of Yin, the forces of darkness. Yang stands for peace and serenity; Yin stands for confusion and turmoil. Yang stands for conservation; Yin stands for destruction. Yang brings about disintegration; Yin gives shape to things....

The pure and lucid element of light is manifested in the upper artifices and the turbid element of darkness is manifested in the lower orifices. Yang, the element of light, originates in the pores. Yin, the element of darkness, moves within the five viscera. Yang the lucid force of light truly is represented by the four extremities- and Yin the

turbid force of darkness stores the power of the six treasures of nature. Water is an embodiment of Yin as fire is an embodiment of Yang. Yang creates the air, while Yin creates the senses, which belong to the physical body When the physical body dies, the spirit is restored to the air, its natural environment. The spirit receives its nourishment through the air, and the body receives its nourishment through the senses

"If Yang is overly powerful, then Yin may be too weak. If Yin is particularly strong, then Yang is apt to be defective If the male force is overwhelming, then there will be excessive heat. If the female force is overwhelming, then there will be excessive cold. Exposure to repeated and severe heat will induce chills. Cold injures the body while heat injures the spirit When the spirit is hurt, severe pain will ensue. When the body is hurt, there will be swelling. Thus, when severe pain occurs first and swelling comes on later, one may infer that a disharmony in the spirit has done harm to the body. Likewise, when swelling appears first and severe pain is felt later on, one can say that a dysfunction in the body has injured the spirit....

"Nature has four seasons and five elements. To grant long life, these seasons and elements must store up the power of creation in cold, heat, dryness, moisture, and wind. Man has five viscera in which these five climates are transformed into joy, anger, sympathy, grief. and fear. The emotions of joy and anger are injurious to the spirit just as cold and heat are injurious to the body. Violent anger depletes Yin; violent joy depletes Yang. When rebellious emotions rise to Heaven the pulse expires and leaves the body When joy and anger are without moderation, then cold and heat exceed all measure, and life is no longer secure. Yin and Yang should be respected to an equal extent.

The Yellow Emperor asked, "Is there any alternative to the law of Yin and Yang?"

Qi Bo answered: "When Yang is the stronger, the body is hot, the pores are closed, and people begin to pant; they become boisterous and coarse and do not perspire. They become feverish, their mouths are dry and sore, their stomachs feel tight, and they die of constipation. When Yang is the stronger, people can endure winter but not summer. When Yin is the stronger, the body is cold and covered with perspiration. People realize they are ill; they tremble and feel chilly. When they feel chilled, their spirits become rebellious. Their stomachs can no long digest food and they die. When Yin is stronger, people can endure summer but not winter. Thus Yin and Yang alternate. Their ebbs and surges vary, and so does the character of the diseases."

The Yellow Emperor asked, "Can anything be done to harmonize and adjust these two principles of nature?" Qi Bo answered: "If one has the ability to know the seven injuries and the eight advantages, one can bring the two principles into harmony. If one does not know how to use this knowledge, his life will be doomed to early decay. By the age of forty the Yin force in the body has been reduced to one-half of its natural vigor and an individual's youthful prowess has deteriorated. By the age of fifty the body has grown heavy. The ears no longer hear well. The eyes no longer see clearly By the age of sixty the life producing power of Yin has declined to a very low level. Impotence sets in The nine orifices no longer benefit each other....

Those who seek wisdom beyond the natural limits will retain good hearing and clear vision. Their bodies will remain light and strong. Although they grow old in years, they will stay able-bodied and vigorous and be capable of governing to great advantage. For this reason the ancient sages did not rush into the affairs of the world. In their pleasures and joys they were dignified and tranquil. They did what they thought best and did not bend their will or ambition to the achievement of empty ends Thus their allotted span of life was without limit, like that of Heaven and earth. This is the way the ancient sages controlled and conducted themselves.

"By observing myself I learn about others, and their diseases become apparent to me. By observing the external symptoms, I gather knowledge about the internal diseases One should watch for things out of the ordinary One should observe minute and trifling things and treat them as if the were big and important. When they are treated the danger they pose will be dissipated. Experts in examining patients judge their general appearance; they feel their pulse and determine whether it is Yin or Yang that causes the disease.... To determine whether Yin or Yang predominates, one must be able to distinguish a light pulse of low tension from a hard. pounding one With a disease of Yang, Yin predominates With a disease of Yin, Yang predominates When one is filled with vigor and strength, Yin and Yang are in proper harmony.(*)

is a well-known Chinese Yin Yang symbol. Sometimes it's called Tai-Chi symbol. The Tai-Chi is from I-Ching. The I-Ching is the greatest foundation of Chinese philosophy. It’s development is from the natural phenomena of our universe. Because I-Ching comes from nature, it should be easy.

The Chinese characters of I-Ching are . The second character means a book, a profound book. The first character means ease or change. Since I-Ching is easy, some people call it as "The Book of Ease" or "The Book of Changes". The original Chinese character of is , which is a symbol combining the sun (top) and moon (bottom). It's easy for people to understand the philosophy by talking about the sun (Yang), moon (Yin) and universe. After observing the universe, ancient Chinese found that the universe is changing every day. Although it changes easily every day, it also has seasonal and annual cycles. From these cycles the unchanging rules are created. However, it's not easy to use the method to find the unchanging rules from the universe and apply on human activities. That's why some people think I-Ching is easy and some don't.

When observing the cycle of the Sun, ancient Chinese simply used a pole about 8 feet long, posted at right angles to the ground and recorded positions of the shadow. Then they found the length of a year is around 365.25 days. They even divided the year's cycle into 24 Segments, including the Vernal Equinox, Autumnal Equinox, Summer Solstice and Winter Solstice, using the sunrise and Dipper positions.

They used six concentric circles, marked the 24-Segment points, divided the circles into 24 sectors and recorded the length of shadow every day. The shortest shadow is found on the day of Summer Solstice. The longest shadow is found on the day of Winter Solstice. After connecting each lines and dimming Yin Part from Summer Solstice to Winter Solstice, the Sun chart looks like below. The ecliptic angle 23 26' 19'' of the Earth can be seen in this chart.

By rotating the Sun chart and positioning the Winter Solstice at the bottom, it will look like this . The light color area which indicates more sunlight is called Yang (Sun). The dark color area has less sunlight (more moonlight) and is called Yin (Moon). Yang is like man. Yin is like woman. Yang wouldn't grow without Yin. Yin couldn't give birth without Yang. Yin is born (begins) at Summer Solstice and Yang is born (begins) at Winter Solstice. Therefore one little circle Yin is marked on the Summer Solstice position. Another little circle Yang is marked on the Winter Solstice position. These two little circles look like two fish eyes.

In general, the Yin Yang symbol is a Chinese representation of the entire celestial phenomenon. It contains the cycle of Sun, four seasons, 24-Segment Chi, the foundation of the I-Ching and the Chinese calendar.(**)   

(*) Translated by Mark Coyle

(**) © Copyright 1999- 2006 Allen Tsai