《黄帝四经·十大经·观》
上有既定的天道，下有周备的万物，中有阴阳二气聚散流动、相因相成地创生一切，圣人只需要顺因其事就可以了。
天道已既，地物乃备。散流乡成，圣人之事。
There is a certain rule in heaven; there are all kinds of things on earth; in the middle is the circulation of Yin and Yang energy, which creates all things through mutual dependence and mutual generation. Sages only need to follow this rule.