Yin & Yang
The concept of Yin and Yang is part of Taoism, an Oriental philosophy of life.
Yin is dark and passive; Yang is light and active. It is said that the two terms come from the shaded and sunny sides of a hill where early Shaolin Monks went to contemplate.
Yin and Yang are also believed to be the source of the Five Elements (Fire, Water, Earth, Air, and Ether), from which all forms are born.
Yin and Yang are symbolically depicted by the figure shown above. The two are equal sections and are joined to form a circle, representing their interdependency for existence (How could we know "Dark" without "Light"?).
The waved boundary between the two represents the fluctuation and motion of their interaction, one that always maintains a harmony in life.
The two dots indicate that one always exists in the other; no form is pure yin or yang.
How do we see Yin and Yang in karate?