Once, Zhuang Zhou dreamed he was a butterfly, fluttering happily from flower to flower, doing as he pleased. He knew nothing of Zhuang Zhou.

Suddenly he woke up, and there he was, solid and unmistakably Zhuang Zhou. But he could not tell: was he Zhuang Zhou who had dreamed he was a butterfly, or a butterfly dreaming he was Zhuang Zhou?

This passage, perhaps the most famous in all of Chinese philosophy, challenges our most basic assumptions about reality. If we cannot distinguish dream from waking, what can we truly know?

Zhuangzi's answer is not nihilism but liberation. Between Zhuang Zhou and the butterfly, there must be some difference — this is called the Transformation of Things. Reality is fluid; our fixed identities are the illusion.