Once upon a time，I，Chuang Tzǔ，dreamt I was a butterfly，fluttering hither and thither，to all intents and purposes a butterfly.I was conscious only of following my fancies as a butterfly，and was unconscious of my individuality as a man.Suddenly，I awaked，and there I lay，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.[28]