Yin and Yang
	• Two opposite forces that emerged from the primordial Dao, and whose interaction defines and regulates the mechanisms of the universe • It is the constant process of changes; countless patterns of existence; the transformations of energy can be systematically charted (The Book of Changes) • In ancient time, Yin and Yang were symbolized by the tiger and the dragon, and in later period by the yin and Yang diagram (taiji diagram)