The Fundamental Concept of Yin-Yang
Taken literally, Yin and Yang describe the two different sides of a hill (or mountain) as the sun shines on it. Upon sunrise, one side of the mountain receives the light of the morning sun (Yang means “sunny side”) while the opposite side lies in shade (Yin means “shady side”). As the sun continues to rise the mountain casts a shadow upon the valley floor below. The sun filled area of the valley is also described by yang and the area lying within the mountain’s shadow is described by yin. As the day progresses the proportions of yang and yin change. At high noon the valley floor surrounding the mountain and the mountain itself is in full sunlight, yang is at its maximum. As anyone has experienced on a hot midday of summer shade is no where to be found, yin is at a minimum. During the afternoon the opposite side of the mountain then becomes cast in shadow. By late afternoon the eastern portion of the valley lies in mountain’s long early evening shadow. As the sun begins to set yin reaches its maximum while yang diminishes.
Before Creation there was only Tao, ineffable, indivisible and undifferentiated. Then, at the very moment of Creation, in an instant, Tao’s uniformity and symmetry were broken. The infant Universe, intensely dense and hot, rapidly expanded outward in all directions. The unfathomable heat began to coalesce into areas of differing temperatures as the early Universe continued to expand and cool. Primordial particles went back and forth in and out of existence; each having a complementary counterpart, a polar opposite of the other.
Where once there was only darkness, now light emerged. Oneness gave way to duality and complementarity. Each emerging complementary (yin-yang) pair – like light (yang) and darkness (yin), hot (yang) and cold (yin), positive (yang) and negative (yin), masculinity (yang) and femininity (yin) – all share an interconnectedness with each influencing the other. When one increases the other is diminished. One becoming more abundant at the expense of the other. When taken together, however, the total partial sums of each complementary pair maintains the balance of the whole. This continual interplay between yin and yang is the driving principle of the Universe and the energy source of Tao.