Aristotle, and W. Rhys Roberts. Rhetoric. Mineola, NY: Dover, 2004. Kindle Electronic Edition.
Book I, chapter 3
Here Aristotle identifies oratory as working in a political, a forensic, or a ceremonial context, depending on the role of the hearer. If the hearer is making a decision about future events the context is political. If the hearer is making a decision about past events the context is forensic. If the hearer is merely listening, the context is ceremonial. In the different contexts the orator has different goals, corresponding to the context (1358b). The rhetorician will need to have at his command all necessary and appropriate proofs necessary to persuade the audience based on justice or injustice. These are the issues that move an audience.