Through the example of a paradigmatic deliberative speech from classical oratory, the paper addresses two fundamental questions of teaching rhetorical reasoning. First, the paper shows that a speech from ancient Greek and Roman political or judicial oratory could provide effective means to teach a variety of argumentation skills, the recognition of fallacies and an awareness of biases in the target audience. Second, the paper uses the speech to consider an elusive problem of rhetorical or critical reasoning instruction, namely how students (...) may use historical models to adapt their knowledge of a case to real-life situations, where a large number of uncertain variables demands a constant awareness of the conditions affecting the audience`s decision and may require a swift change in the argumentative strategy. The paper will argue that the application of a new model of strategic reasoning called heuristic rhetoric to Cicero`s speech could illustrate a workable solution to both problems. (shrink)