Rhetoric and analogies

•Rhetoric can change people's minds (opinions or beliefs) without providing new information.•Rhetoric may do this by calling attention to similarities between situations the listener understands.•We offer two models of analogies that capture how rhetoric can change minds without offering new information.

The art of rhetoric may be defined as changing other people's minds (opinions, beliefs) without providing them new information. One technique heavily used by rhetoric employs analogies. Using analogies, one may draw the listener's attention to similarities between cases and to re-organize existing information in a way that highlights certain regularities. In this paper we offer two models of analogies, discuss their theoretical equivalence, and show that finding good analogies is a computationally hard problem.