Once Chuang Chou dreamed he was a butterfly, a butterfly flitting and fluttering around, happy with himself and doing as he pleased. He did not know he was Chuang Chou. Suddenly he woke up and there he was, solid and unmistakably Chuang Chou. But he did not know if he was Chuang Chou who had dreamed he was a butterfly, or a butterfly dreaming he was Chuang Chou. Between Chuang Chou and a butterfly there must be some distinction! This is called the Transformation of Things.