structural:reformatting, linguistic:paraphrasing, linguistic:voice_change
"The Debate on the Joy of Fish"

Chapter 17 contains a well-known exchange between Zhuang Zhou and Huizi, featuring a heavy use of wordplay; it has been compared to a Socratic dialogue.

莊子與惠子遊於濠梁之上。莊子曰：儵魚出遊從容，是魚樂也。 Zhuangzi and Huizi were enjoying themselves on the bridge over the Hao River. Zhuangzi said, "The minnows are darting about free and easy! This is how fish are happy." 惠子曰：子非魚，安知魚之樂。莊子曰：子非我，安知我不知魚之樂。 Huizi replied, "You are not a fish. How do you know that the fish are happy?" Zhuangzi said, "You are not I. How do you know that I do not know that the fish are happy?" 惠子曰：我非子，固不知子矣；子固非魚也，子之不知魚之樂全矣。 Huizi said, "I am not you, to be sure, so of course I don't know about you. But you obviously are not a fish; so the case is complete that you do not know that the fish are happy." 莊子曰：請循其本。子曰汝安知魚樂云者，既已知吾知之而問我，我知之濠上也。 Zhuangzi said, "Let's go back to the beginning of this. You said, How do you know that the fish are happy; but in asking me this, you already knew that I know it. I know it right here above the Hao."

The precise point Zhuang Zhou intends to make in the debate is not entirely clear. The text appears to stress that "knowing" a thing is simply a state of mind: moreover, that it is not possible to determine whether "knowing" has any objective meaning. This sequence has been cited as an example of Zhuang Zhou's mastery of language, with reason subtly employed in order to make an anti-rationalist point.