《老子·道经·第二十九章》
世人秉性不一，有的前行有的后随；有的气缓，有的气急；有的刚强，有的羸弱；有的安定，有的危险。
夫物或行或随；或嘘或吹；或强或羸；或载或隳。
The nature of man is different, some people go ahead, some follow; some are slow, some are quick; some are strong, some are weak; some are steady, some are precarious.