Rhetoric is often defined as the art of persuasion, but it is more precisely the study of how meaning is constructed in situations where people must interpret, judge, and respond without complete certainty. As Sharon Crowley and Debra Hawhee explain in Ancient Rhetorics for Contemporary Students, rhetorical activity arises within particular contexts and depends on audiences who bring their own beliefs, expectations, and values to the act of interpretation. Arguments do not exist in isolation; they emerge through shared assumptions, points of disagreement, and judgments about credibility.
This glossary approaches rhetoric through a series of concepts – exigence, stasis, commonplace, enthymeme, and ethos – that together describe how persuasion operates in practice. Each term identifies a different aspect of rhetorical activity: why discourse becomes necessary, what is at issue, what assumptions are shared, how arguments are structured, and why they are believed. Taken together, these concepts show that persuasion often depends less on formal logic than on what audiences already accept, what remains unstated, and whom they trust.
To illustrate these concepts, this glossary draws on widely recognized films as examples of rhetorical contexts. Films such as Jaws, The Matrix, and Contact have reached broad audiences and continue to be viewed across time, making them shared cultural texts through which rhetorical dynamics can be examined. As Walter R. Fisher argues in “Narration as a Human Communication Paradigm,” “some dramatic and literary works do, in fact, argue,” suggesting that narrative forms can present claims that audiences interpret and evaluate. These films do more than tell enduring stories; they stage situations in which viewers must make judgments about what is true, what matters, and who is credible.
The use of film also reflects the importance of accessibility in rhetorical study. While not all readers will have seen each film in full, the examples are presented in a way that allows the rhetorical situation to be understood without specialized knowledge. This approach assumes an audience interested in rhetoric as a field and aims to demonstrate how its key concepts operate in familiar cultural contexts.
The sources used in this glossary combine foundational and contemporary approaches to rhetoric. Crowley and Hawhee provide a framework for classical rhetorical concepts, while Silva Rhetoricae offers concise definitions that clarify key terms. Articles such as those by Danielle DeVasto and S. Scott Graham illustrate how these concepts function in modern contexts, particularly in public and technical communication. Additional sources, including works by Pamela Douglas, William Goldman, and Wendy McElroy, extend these ideas into professional and personal domains, showing how rhetorical principles inform both public discourse and individual practice.
Rhetoric matters because it helps explain how people make decisions in situations where evidence is incomplete and agreement is uncertain. Disagreements often persist because participants are not all addressing the same question, relying on different assumptions, or evaluating credibility differently. By examining what is taken for granted, what is left unsaid, and how trust is established, rhetorical analysis provides a way to understand why some arguments persuade while others fail. This glossary offers one approach to that analysis, using familiar narratives to illustrate the structures that shape persuasion.