The originality of the Library of History seeking to confer to its author the authorship of his writings. Far from being a mere copyist, Diodorus is a historian-educator that seeks to instruct his readers giving a utility character in the learning of a correct and just life. The recurrent terms parádoxa and thaumázein meaning amazement, admiration and marvelous-ment, show how humanity was capable of overcoming the difficulties of a hostile existence and becoming apt to live in society. Diodorus dedicates into narrating the history of the world, by setting the example of great men, especially in the battle field. Parádoxa does not signify marvelous or amazed and, allied to Fortune, it gains the meaning of “contrary to all expectations”.The moralizing character from the Library attributes to history an extremely important role, for it is up to it demonstrate who deserves to figurate in glory or abasement through the perennially that only history can confer. Diodorus behaves as a judge that points out those who, in their acts, have succeeded and made mistakes, not only narrating the facts, but incentivizing his reader to a virtuous behavior and to a moral aret?.