"There you are!" Chuang Tzu's friend greeted him. "I thought by now you would be telling everybody another one of your stories. Why so quiet?"
"There is a question on my mind," said Chuang Tzu, "a question about existence."
"I see. Would you like me to leave you alone to your thoughts?"
"No, let me share it with you. Perhaps you can provide me with your perspective."
"My perspective is of little value, but I would be glad to listen." He pulled up a chair.
"I was out for a stroll late in the afternoon," said Chuang Tzu. "I went to one of my favorite spots under a tree. I sat there, thinking about the meaning of life. It was so warm and pleasant that I soon relaxed, dozed off, and drifted into a dream. In my dream, I found myself flying up above the field. I looked behind me and saw that I had wings. They were large and beautiful, and they fluttered rapidly. I had turned into a butterfly! It was such a feeling of freedom and joy, to be so carefree and fly around so lightly in any way I wished. Everything in this dream felt absolutely real in every way. Before long, I forgot that I was ever Chuang Tzu. I was simply the butterfly and nothing else."
"I've had dreams of flying myself, but never as a butterly," Chuang Tzu's friend said. "This dream sounds like a wonderful experience."
"It was, but like all things, it had to end sooner or later. Gradually, I woke up and realized that I was Chuang Tzu after all. This is what puzzles me."
"What is so puzzling about it? You had a nice dream, that's all there is to it."
"What if I am dreaming right now? This conversation I am having with you seems real in every way, but so did my dream. I thought I was Chuang Tzu who had a dream of being a butterfly. What if I am a butterfly who, at this very moment, is dreaming of being Chuang Tzu?"
"Well, I can tell you that you are actually Chuang Tzu, not a butterfly."
Chuang Tzu smiled: "You may simply be part of my dream, no more or less real than anything else. Thus, there is nothing you can do to help me identify the distinction between Chuang Tzu and the butterfly. This, my friend, is the essential question about the transformation of existence."