 Though tradition has treated Laozi and Zhuangzi as the Socrates and Plato of ‘Daoism,’ the use of Lao-Zhuang to identify a strain of thought may have become common only as with Neo-Daoism in the 3rd Century AD. Not only is it true that “Zhuangzi never knew he was a Daoist”, (Graham 1981, 128) he probably also didn’t know anything about the Laozi. However, writers responsible for later chapters of the Zhuangzi established the first connection between the two texts. A large chunk of the “outer” chapters use the character of Laozi as spokesman for a closely related meta-ethical position and occasionally echoes the style and attitudes of the Daode Jing—though it seldom quotes directly from any extant version. Common themes, tropes and modes of expression seem to link the authors of the outer chapters with Daode Jing. One plausible speculation is that anonymous students of the Zhuangzi, working after his death, were “developing” the Zhuangzi text while in contact with the group anonymously composing the Daode Jing. They seemingly shaped each other’s themes, expressions and ideas. See further discussion in  Texts and Textual Theory.  