《淮南子·泰族训》
天时不可能只有一个季节，大地也不可能只有一种利益，人也不可能只有一种本事，因此圣人的事业不能不是头绪繁多，旨趣行为不能不是多方面的。
天不一时，地不一利，人不一事，是以绪业不得不多端，趋行不得不殊方。
There is no one season in the year, nor is there one kind of produce from the earth; nor are men all of one pattern. Therefore what the sage does is far from being simple, and his aims and activities far from being confined to one direction.