Aristotle

As mentioned already, rhetoric itself was the subject of much debate in classical Greece, with the Sophists on one side and Socrates, Plato, and Aristotle on the other, though they could arguably be classed as Sophists as well.  Like Plato, Aristotle saw rhetoric and poetry as tools that were too often used to manipulate others by trading on emotion and neglecting facts.  Aristotle’s was a rhetoric based in the pursuit of knowledge; one of his most important contributions identifying rhetoric as one of the three key elements of philosophy, along with logic and dialectic.  For Aristotle, Rhetoric is a tool for practical debate; it is a means for persuading a general audience using probable knowledge to resolve practical issues–in other words, for negotiation or arguments that end with some decision on a course of action. In contrast, dialectic is a method  of investigation and discovery, the results of which are used as evidence by rhetors. Dialectic and rhetoric together create a partnership for a system of persuasion based on knowledge instead of manipulation of emotion.

Ars Rhetorica — Books 1 and 2, and Book 3, Chapter 7

Cicero

Borne 106 BCE, 60 miles south of Rome.  Cicero is largely credited with having introduced the Greek rhetorical and philosophical traditions and texts into Roman culture.  Cicero was an active and powerful political figure, largely because he was a brilliant orator.  In fact he was consider so powerful a speaker as to be dangerous, leading to his being exiled on one occasion, and later assassinated.

De Oratore — Book 1, Chapters 1-35.  Note, each chapter is only about .5-1 pages.

Quintillian

Born (ca. 35 – ca. 100); a Roman rhetorician from Hispania, Quintilian ran a public school of Rhetoric subsidized by the emperor, Vespasian, and is another who wrote explicitly about pedagogical methods.  Quintilian survived several emperors, including Domitian who was know for his cruelty and for having encouraged a culture of secret police and informants in the republic.  Thus in his work far less attention is focused on the practical uses of Rhetoric and far more on pedagogy and formal qualities.

Institutes of Oratory — Books 2 and 10