Taijitu prior to 1686. It combines several abstract shapes, including a "Taiji" symbol illustrating the mutual complement of man and woman. In socialist times, it was alternatively interpreted as two fish symbolizing vigilance, because fish never close their eyes. The modern symbol has also been widely used in martial arts, particularly t'ai chi ch'uan (Taijiquan), and Jeet Kune Do, since the 1970s. In this context, it is generally used to represent the interplay between hard and soft techniques. The dots in the modern "yin-yang symbol" have been given the additional interpretation of "intense interaction" between the complementary principles. Similarities can be
Yin and yang a mountain and a valley. Yin (literally the 'shady place' or 'north slope') is the dark area occluded by the mountain's bulk, while yang (literally the "sunny place' or "south slope") is the brightly lit portion. As the sun moves across the sky, yin and yang gradually trade places with each other, revealing what was obscured and obscuring what was revealed. Yin is characterized as slow, soft, yielding, diffuse, cold, wet, and passive; and is associated with water, earth, the moon, femininity, and night time. Yang, by contrast, is fast, hard, solid, focused, hot, dry, and active; and is associated