persuasive messages), and delivery (the gestures, pronunciation, tone and pace used when presenting the persuasive arguments). In the rhetoric field, there is an intellectual debate about Aristotle's definition of rhetoric. Some believe that Aristotle defines rhetoric in On Rhetoric as the art of persuasion, while others think he defines it as the art of judgment. Rhetoric as the art of judgment would mean the rhetor discerns the available means of persuasion with a choice. Aristotle also says rhetoric is concerned with judgment because the audience judges the rhetor's ethos. One of the most famous of Aristotelian doctrines was the idea of topics (also referred to as common topics or commonplaces). Though the term had a wide range of application (as a memory technique or compositional exercise, for example) it most often referred to the "seats of argument"—the list of categories of thought or modes of reasoning—that a speaker could use to generate arguments or proofs. The topics were thus a heuristic or inventional tool designed to help speakers categorize and thus better retain and apply frequently used types of argument. For example, since we often see effects as "like" their causes, one way to invent an argument (about a future effect) is by discussing the cause (which it will be "like"). This and other rhetorical topics derive from Aristotle's belief that there are certain predictable ways in which humans (particularly non-specialists) draw conclusions from premises. Based upon and adapted from his dialectical Topics, the rhetorical topics became a central feature of later rhetorical theorizing, most famously in Cicero's work of that name. Cicero For the Romans, oration became an important part of public life. Cicero (106–43 BC) was chief among Roman rhetoricians and remains the best known ancient orator and the only orator who both spoke in public and produced treatises on the subject. Rhetorica ad Herennium, formerly attributed to Cicero but now considered to be of unknown authorship, is one of the most significant works on rhetoric and is still widely used as a reference today. It is an extensive reference on the use of rhetoric, and in the Middle Ages and Renaissance, it achieved wide publication as an advanced school text on rhetoric. Cicero is considered one of the most significant rhetoricians of all time, charting a middle path between the competing Attic and Asiatic styles to become considered second only to Demosthenes among history's orators. His works