Zhuang Zhou莊周(BC 369~286) Philosopher or Daoist.
“Once upon a time, I, Zhunag Zhou, dreamt I was a butterfly, fluttering hither and thither, to all intents and purposes a butterfly. I was conscious only of my happiness as a butterfly, unaware that I was myself. Soon I awaked, and there I was, veritably myself again. Now I do not know whether I was then a man dreaming I was a butterfly, or whether I am now a butterfly, dreaming I am a man. Between a man and a butterfly there is necessarily a barrier. The transition is called Metempsychosis.” _Butterfly Phrase in Zhuang Zhi