Rhetoric has had many definitions; no simple definition can do it justice. In fact, the very act of defining has itself been a central part of rhetoric: It appears among Aristotle's topoi, heuristics for rhetorical inventio. For Aristotle, rhetoric is the art of practical wisdom and decision making, a counterpart to logic and a branch of politics. The word is derived from the ancient Greek eiro, which means "I say." In its broadest sense, rhetoric concerns human discourse.

Rhetoric as a Civic Art

In eras of European history, rhetoric concerned itself with persuasion in public and political settings such as assemblies and courts. Because of its associations with democratic institutions, rhetoric is commonly said to flourish in open and democratic societies with rights of free speech, free assembly, and political enfranchisement for some portion of the population.

Rhetoric as a Course of Study

As a course of study, rhetoric trains students to speak and/or write effectively. The rhetorical curriculum is nearly as old as the rhetorical tradition itself. Over its many centuries, the curriculum has been transformed in a number of ways, but, in general, it has emphasized the study of principles and rules of composition as a means for moving audiences. In Greece, rhetoric originated in a school of pre-Socratic philosophers known as Sophists circa 600 BC. It was later taught in the Roman Empire and during the Middle Ages as one of the three original liberal arts or trivium (along with logic and grammar).

Rhetoric as Epistemology

The relationship between rhetoric and knowledge is one of its oldest and most interesting problems. The contemporary stereotype of rhetoric as "empty speech" or "empty words" reflects a radicial division of rhetoric from knowledge, a division that has had influential adherents within the rhetorical tradition, most notably Plato in ancient Athens, and Peter Ramus in 16C Renaissance Europe. It is a division that has been strongly associated with Enlightenment thinking about language.

Most rhetoricians, however, see a closer relationship between rhetoric and knowledge. Researchers in the rhetoric of science, for instance, have shown how the two are difficult to separate, and how discourse helps to create knowledge. This perspective is often called "epistemic rhetoric," where communication among interlocutors is fundamental to the creation of knowledge in communities.

Emphasizing this close relationship between discourse and knowledge, contemporary rhetoricians have been associated with a number of philosophical and social scientific theories that see language and discourse as central to, rather than in conflict with knowledge-making (See Critical Theory, Post-structuralism, Hermeneutics, Reflexivity)''.

The Scope of Rhetoric

Contemporary studies of rhetoric address a more diverse range of domains than was the case in ancient times. While classical rhetoric trained speakers to be effective persuaders in public forums and institutions like courtrooms and assemblies, contemporary rhetoric investigates human discourse writ large. Rhetoricians have studied the discourses of a wide variety of domains, including the natural and social sciences, fine art, religion, journalism, fiction, history, cartography, and architecture, along with the more traditional domains of politics and the law.