Rhetorica ad Herennium

The Rhetorica ad Herennium (Rhetoric: For Herennius), formerly attributed to Cicero or Cornificius, but in fact of unknown authorship, sometimes ascribed to an unnamed doctor, is the oldest surviving Latin book on rhetoric, dating from the late 80s BC., and is still used today as a textbook on the structure and uses of rhetoric and persuasion.

The Rhetorica ad Herennium was addressed to Gaius Herennius (otherwise unknown). The Rhetorica remained the most popular book on rhetoric during the Middle Ages and the Renaissance. It was commonly used, along with Cicero's De Inventione, to teach rhetoric, and over one hundred manuscripts are extant. It was also translated extensively into European vernacular languages and continued to serve as the standard schoolbook text on rhetoric during the Renaissance. The work focuses on the practical applications and examples of rhetoric. It is also the first book to teach rhetoric in a highly structured and disciplined form.

Its discussion of elocutio (style) is the oldest surviving systematic treatment of Latin style, and many of the examples are of contemporary Roman events. This new style, which flowered in the century following this work's writing, promoted revolutionary advances in Roman literature and oratory. However, according to some analysts, teaching oratory in Latin was inherently controversial because oratory was seen as a political tool, which had to be kept in the hands of the Greek-speaking upper class. The Rhetorica ad Herennium can be seen as part of a liberal populist movement, carried forward by those, like L. Plotius Gallus, who was the first to open a school of rhetoric at Rome conducted entirely in Latin. He opened the school in 93 BCE. The work contains the first known description of the method of loci, a mnemonic technique. Ad Herennium also provides the first complete treatment of memoria (memorization of speeches).

According to the work, there are three types of causes that a speaker would address:

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