There existed a psychotherapist who believed that many of the problems people brought to him were characterized by the existence of ‘fish’ in their dreams. One day a client came to him and was discussing the problems he had. ”Tell me,” said the psychotherapist, “did you dream last night?” “I might have done,” replied the client. “And tell me, in this dream was there a river?” “I don’t think so,” replied the client. “Well, was there any water, if not a river?” “I guess there might have been.” “And was there a pool on the ground?” “I couldn’t be certain but it’s possible,” the client replied. “And in this pool could there have been a fish?” “I can’t rule out the possibility that there might have been a fish.” “Aha!” said the psychotherapist. “I knew it!”