In Chinese philosophy, the yin-yang is a symbol that illustrates the concept of the inter-connectedness and interdependence of opposing contrary forces in the natural world.According to this philosophy, these forces give rise to each other.
Natural dualities such as light and dark, high and low, hot and cold, fire and water, life and death, male and female, and sun and moon are seen as physical manifestations of the yin-yang concept.
The yin-yang is a primary guideline of traditional Chinese medicine and an important principle of various different forms of Chinese martial arts and exercise like Thai Chi. Yin-Yang are always considered to be opposite and equal qualities in Daoist philosophy. They are bound together as parts of a mutual whole.
The yin-yang is a symbol that has always been related to Chinese philosophies and teachings, but it already existed 700 years before it appeared in China! It first appeared on the Notitia Dignitatum, a unique document from Roman imperial diplomatic missions. The Notitia is one of very few surviving documents of Roman government, and it details the administrative organisation of the Eastern and Western Roman Empires.
The document contains the earliest known depictions of the diagram which later came to be known as the yin-yang. Shield bearers in the infantry units had a shield design with the same dynamic, clockwise version of the symbol.
