Take a fairy tale, like Little Red Riding Hood. The text starts from a given set of characters and situations — a little girl, a mother, a grandmother, a wolf, a wood — and through a series of finite steps arrives at a solution. Certainly, you can read the fairy tale as an allegory and attribute different moral meanings to the events and to the actions of the characters, but you cannot transform Little Red Riding Hood into Cinderella. Finnegans Wake is certainly open to many interpretations, but it is certain that it will never provide you with a demonstration of Fermat’s last theorem, or with the complete bibliography of Woody Allen. This seems trivial, but the radical mistake of many deconstructionists was to believe that you can do anything you want with a text. This is blatantly false.
The text is open, but it’s not THAT open. And the good news is that books will survive.