This was Twains most serious and private book. He kept it locked up, considered it to be his Bible, and spoke of it as such to friends. He had rewritten it many times before being satisfied, but still chose not to release it until after his death. It appears in the form of a dialogue between an old man and a young man who discuss who and what mankind really is. We consider ourselves as free and autonomous people, yet this book puts forth the ideas that 1) We are nothing more than machines and originate nothing not even a single thought; 2) All conduct arises from one motive self-satisfaction; 3) Our temperament is completely permanent and unchangeable; and 4) Man is of course a product of heredity, and our future, being fixed, is irrevocable -- which makes life completely predetermined. If these points are true, then buying and reading this book is not in your control, but simply must be done because it was meant to be. If these points are not true you can still make an independent decision to enjoy a great book by a legendary writer.