Appropriateness is the key to persuasion: a speech can only be convincing when it takes into account the opinions of the audience and the concrete situation. But how can rhetorical theory– which like any other theory has to abstract– grasp appropriateness as a phenomenon? What concepts did it develop in order to achieve this? The central thesis of the volume is that although it has hardly been analysed in the past, appropriateness always plays a central role in rhetoric.