《论衡·卷十八·自然篇》
所以说：政治完美，君臣彼此忘怀于无为之治，鱼类彼此忘怀于水中，兽类彼此忘怀于林中，人类彼此忘怀于世上，因而称为自然。
故曰： 政之适也，君臣相忘於治，鱼相忘於水，兽相忘於林，人相忘於世。
Therefore, it is said that when politics is perfect, the monarch and his ministers forget each other in a state of inaction, the fish forget each other in the water, the beasts forget each other in the forest, and humans forget each other in the world, and therefore it is called nature.