Yin Yang had been understood for many centuries, but was systematically elaborated and written down by Tsou Yen of the Yin Yang (Naturalist) School in the Warring States Period (476-221 BC). The Eight Trigrams were combined to form 64 hexagrams, symbolizing all possible phenomena of the Universe. With addition of an extra line, the Eight Trigrams (Ba Gua) were formed, illustrating all the directions. Yin Yang is the fundamental principle, and the most important theory in TCM, underlying all physiology, pathology & treatment.Ĭombining the two, we have the four stages of Yin and Yang. For example: Spring only comes when winter is finished. One can change into the other, but it is not a random event, happening only when the time is right. 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. Relative levels of Yin Yang are continuously changing. The classics state: "Yin creates Yang and Yang activates Yin". For Example: no energy without matter, no day without night. They constantly transform into each other. Yin contains seed of Yang and vise versa. Just as a state of total Yin is reached, Yang begins to grow. The Tai Ji (Supreme Ultimate) diagram shows the relationship of Yin & Yang and illustrates interdependence on Yin & Yang. Interdependent: Can not exist without each other.Yin and Yang are never static but in a constantly changing balance.
For example: Water is Yin relative to steam but Yang relative to ice. This opposition is relative, and can only be spoken of in relationships. 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. Four Main Aspects of Yin and Yang Relationship