Memoria was the term for aspects involving memory in Western classical rhetoric. The word is Latin, and can be translated as "memory".
It was one of five canons in classical rhetoric (the others being inventio, dispositio, elocutio, and pronuntiatio) concerned with the crafting and delivery of speeches and prose.
The art of rhetoric grew out of oratory, which was the central medium for intellectual and political life in ancient Greece. Legal proceedings, political debates, philosophical inquiry were all conducted through spoken discourse. Many of the great texts from that age were not written texts penned by the authors we associate them with, but were instead orations written down by followers and students. In Roman times, while there was a much greater body of written work, oration was still the medium for critical debate. Unlike public speakers of today, who use notes or who read their speeches, good orators were expected to deliver their speeches without such aids.
Memoria was the discipline of recalling the arguments of a discourse. It generally received less attention from writers than other parts of rhetoric, as there is less to be said about the subject. However, the need to memorize speeches did influence the structure of discourse to some extent. For example, as part of dispositio, some attention was paid to creating structures (such as the divisio, an outline of the major arguments of a discourse) that would also aid memory. Some writers also discussed the use of various mnenomic devices to assist speakers.
But rhetoricians also viewed memoria as requiring more than just rote memorization. Rather, the orator also had to have at his command a wide body of knowledge to permit improvisation, to respond to questions, and to refute opposing arguments. Where today's speech-making tends to be a staged, one-way affair, in former times, much oration occurred as part of debates, dialogues, and other settings, in which orators had to react to others. Moreover, rhetoricians also recognized that the credibility of a speaker depended not just on the strength of his prepared arguments, but on the audience's perceptions of the speaker. In Greece, Rome, and the Renaissance, a speaker's familiarity of many areas of learning was seen as a virtue.
When the Humanists took up the ideas on memory found the writings of Classical authors, memoria played an important role in the pedagogical system. Texts were learned first by rote memorization, then re-read for meaning. Children's ability to memorize was aided by "memory tables", which were first available in manuscript form, and were, from the 1470s onwards, some of the first products of the printing press. (Source: Paul Gehl, A Moral Art: Grammar, Society, and Culture in Trecento Florence (1993)