Yin and Yang is one of the most fundamental concepts in Traditional Chinese Medicine, as it is the foundation of diagnosis and treatment. The earliest reference to Yin and Yang is in the I Ching (Book of Changes) in approximately in 700 BC. In this work, all phenomena are said to be reduced to Yin-Yang.
Translations: 1. female, passive, negative principle in nature 2. the moon 3. shaded orientation 4. north or shady side of a hill 5. south of a river.
Translations: 1. positive, active, male principle in nature 2. south or sunny side of a hill 3. north of a river.
The ancients observed 2 phases of constant cyclical change. Yin constantly changes into Yang & back into Yin again. This can be seen in the changes of four seasons, and the changes throughout a single day (24 Hour Cycle), as seen below.
(12 PM corresponds to Utmost Yang, while 12AM corresponds to Utmost Yin)
Four Main Aspects of Yin and Yang Relationship
- Yin-Yang are opposites
They are either on the opposite ends of a cycle, like the seasons of the year, or, opposites on a continuum of energy or matter. This opposition is relative, and can only be spoken of in relationships. For example: Water is Yin relative to steam but Yang relative to ice. Yin and Yang are never static but in a constantly changing balance.
- Interdependent: Can not exist without each other
The Tai Ji (Supreme Ultimate) diagram shows the relationship of Yin & Yang and illustrates interdependence on Yin & Yang. Nothing is totally Yin or totally Yang. Just as a state of total Yin is reached, Yang begins to grow. Yin contains seed of Yang and vise versa. They constantly transform into each other. For Example: no energy without matter, no day without night.
The classics state: "Yin creates Yang and Yang activates Yin".
- Mutual consumption of Yin and Yang
Relative levels of Yin Yang are continuously changing. Normally this is a harmonious change, but when Yin or Yang are out of balance they affect each other, and too much of one can eventually weaken (consume) the other.
Four (4) possible states of imbalance:
- Preponderance (Excess) of Yin
- Preponderance (Excess) of Yang
- Weakness (Deficiency) of Yin
- Weakness (Deficiency) of Yang
- Inter-transformation of Yin and Yang.
One can change into the other, but it is not a random event, happening only when the time is right. For example: Spring only comes when winter is finished.