“Credibility really is kind of metaphysical: We have to take a little leap of faith to get there. The main root of “credible,” after all, is the Latin word for “belief.” Aristotle thought the best way to inspire such faith was to seem like a good person: “Persuasion is achieved by the speaker’s personal character,” he wrote in “Rhetoric,” “when the speech is so spoken as to make us think him credible.” The audience is inclined to trust someone it already thinks well of.”
Michelle Dean, NYT Magazine: “It’s Getting Harder to Sort the ‘Credible’ from the Incredible”