The Philosophy of Acupuncture and Traditional Chinese Medicine
Ancient Chinese Taoist masters studied the flow of nature and organized the Universe into two main types of matter :
Yin and Yang
Yin is composed of everything heavy, dense, cold, dark, slow, and descending.
Yang is composed of light, ethereal, hot, bright, fast, and ascending.
These two forces need the other to exist. Without dark there would be no light. Without cold there would be no heat. Everything is relative to its opposite.
In the body, these forces must maintain harmony and balance or dis-ease will arise. If there is too much cold in one particular part of the body, we must add heat. If the circulation is too slow, we must speed it up, and vice versa. Everything in the body must maintain a certain degree of balance to function in a healthy manner.
The oldest book known to man is the 'I Ching - Book of Changes'. This book describes the many various configurations of Yin and Yang, as depicted by broken (Yin) and unbroken (Yang) lines, of which there are sixty-four hexagrams or groupings of six lines.
Each hexagram is really comprised of two separate trigrams (group of three lines) also known as 'gua'. There are eight different 'Gua' which are known as the 'Ba Gua', meaning 'eight trigrams'.
Each 'Gua' represents a theme in nature. Earth, Thunder, Water, Lake, Heavens, Wood, Fire, and Mountain. Since there are eight 'gua', there are sixty-four possible combinations, (8 x 8 = 64).
Along with the sixty-four hexagrams representing all of the various interactions of Yin and Yang energetic forces, there are the 'Five Elements'. These are Water, Wood, Fire, Earth, and Metal. If you think about it, each element gives birth to the element following it. Water feeds wood. Wood burns, making fire. Fire creates ash which becomes Earth. Earth condenses and individualizes into single elements or metals, like those found in the Periodic Table of elements in your chemistry books. Metals represent single elements such as oxygen and hydrogen which come together to form H2O, or Water.
Each of these 'Five Elements' represents one of our internal organs.