| “ | 昔者莊周夢為蝴蝶，栩栩然蝴蝶也，自喻適志與，不知周也。俄然覺，則蘧蘧然周也。不知周之夢為蝴蝶與，蝴蝶之夢為周與？周與蝴蝶則必有分矣。此之謂物化。 | ” |
Another well-known part of the book, which is also found in Chapter 2, is usually called "Zhuangzi dreamed he was a butterfly" (莊周夢蝶 Zhuāng Zhōu mèng dié). Again, the names have been changed to pinyin romanization for consistency:
Once Zhuangzi dreamt he was a butterfly, a butterfly flitting and fluttering around, happy with himself and doing as he pleased. He didn't know he was Zhuangzi. Suddenly he woke up and there he was, solid and unmistakable Zhuangzi. But he didn't know if he was Zhuangzi who had dreamt he was a butterfly, or a butterfly dreaming he was Zhuangzi. Between Zhuangzi and a butterfly there must be some distinction! This is called the Transformation of Things. (2, tr. Burton Watson 1968:49)
This hints at many questions in the philosophy of mind, philosophy of language, and epistemology.[vague] The name of the passage has become a common Chinese idiom, and has spread into Western languages as well. It appears, inter alia, as an illustration in Jorge Luis Borges' famous essay "A New Refutation of Time", and may have inspired H. P. Lovecraft's 1918 short story "Polaris". It also appears in Victor Pelevin's philosophical novel Buddha's Little Finger.
Zhuangzi's philosophy was very influential in the development of Chinese Buddhism, especially Chán (also known as Zen).