the transformation of material things

 

.

Once upon a time, I, Chuang Chou, 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 Chou. 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 distinction. The transition is called the transformation of material things.

—Chuang Chou
Lin Yutang translation

.