"The reality at least allows doubt. The dream does not allow doubt. In fact, that is the only criterion to distinguish between them. If you can doubt, it means you are awake. If you cannot doubt, it means you are fast asleep. A very strange criterion, but that is the only criterion.

"Because all the religions are against doubt, they have destroyed the most fundamental criterion available to man. All the religions of the world, without exception, insist on believing. And belief is the antidote to doubt.

"One can condition oneself to such an extent that doubt does not arise, but then you have lost the only criterion you have for making the distinction between what is real and what is unreal. Dreams cannot be doubted – reality can be doubted.

"In the life of Chuang Tzu comes one of the most beautiful incidents. One morning he was sitting in his bed – very sad, very serious…and sadness and seriousness were absolutely against his nature, his philosophy. He was the most hilarious man. He has written the most absurd stories with such great significance – illogical, irrational, but yet pointing to the truth.

"His disciples gathered and they were worried, 'It has never happened, he has never been sad. He is a man of laughter, and he is looking so serious. Is he sick, or has something gone wrong?'

"Finally some disciple asked, 'What is the matter, master?'

"Chuang Tzu said very seriously, 'The matter is almost beyond my comprehension, and I don't think you will be in any way helpful to me, but still I will tell you. In the night I dreamt that I had become a butterfly.'

"All the disciples laughed and said, 'That is nothing to be serious about. It was only a dream, so you don't have to be so worried. Now you are awake; the dream is finished.'

"He said, 'You first listen to the whole story. When I woke up this morning, a strange idea arose within my heart: 'If Chuang Tzu can become a butterfly in his dream, why cannot a butterfly become Chuang Tzu in her dream? There seems to be no logical reason why a butterfly cannot dream to be Chuang Tzu.'

"Still the disciples said, 'You don't need to worry about butterflies! Let them dream whatever they want to dream, but why are you sad?'

"Chuang Tzu said, 'You still have not grasped the problem."