Rhetoric is the art and study of the use of language with persuasive effect. In Aristotle's systematization of rhetoric, one important aspect of rhetoric to study and theorize was the three persuasive audience appeals: logos, pathos, and ethos, as well as the five canons of rhetoric: invention or discovery, arrangement, style, memory, and delivery. Along with grammar and logic or dialectic, rhetoric is one of the three ancient arts of discourse. From ancient Greece to the late 19th Century, it was a central part of Western education, filling the need to train public speakers and writers to move audiences to action with arguments.
A rhetorical question is a figure of speech in the form of a question posed for its persuasive effect without the expectation of a reply. Rhetorical questions encourage the listener to think about what the (often obvious) answer to the question must be. When a speaker states, "How much longer must our people endure this injustice?", no formal answer is expected. Rather, it is a device used by the speaker to assert or deny something. (e.g.: "Why me?") While amusing and often humorous, rhetorical questions are rarely meant for pure, comedic effect. A carefully crafted question can, if delivered well, persuade an audience to believe in the position(s) of the speaker.