The present article will critically discuss various approaches to irony originating from different disciplines. Besides traditional definitions of ironic speech dating back to Roman times as well as present-day linguistic models, it will also deal with irony from a psychological perspective. As this inquiry will show, all the approaches under discussion are exclusively monologic and so do not provide a full account of the communicative functions of ironic expressions in language use. The paper therefore suggests a dialogic perspective which highlights the communicative effects of ironic talk neglected by previous models. As a result, it will be shown that irony needs not merely be used by a speaker to bypass direct criticism in order to avoid conflict or to compensate for psychological incongruities but as a skilful rhetorical device to motivate the interlocutor to act for the good of herself or of other people around.