As we have seen, Plato and Aristotle had a great deal to say about memory and most of their discussions related memory to theories of knowing and being. But it was the technique of memorising by impressing ‘places’ (loci) and ‘images (imagines) on memory, the art of mnemotechnics, that was passed on to orators in Rome and thence to the European rhetorical tradition. Before the age of printing a trained memory was, of course, vitally important. In his De Oratore, Cicero tells the story of how Simonides of Ceos had trained his memory by place images which enabled him to recall who was where at a banquet which ended in tragedy: after Simonides had departed, the roof fell in and crushed all the guests. And Cicero speaks of memory as one of the five parts of rhetoric. Whereas Aristotle the philosopher sees rhetoric as subordinate to logic or dialectic, Cicero the politician and public orator reverses their superiority: demonstration is for him ancillary to persuasion. He seems unaware of Aristotle's discussion of imagination and memory beyond what little is said explicitly in Aristotle's rhetorical and logical works.

Two other descriptions of this art of memory, both in Latin treatises on rhetoric, have come down to us: the anonymous Ad Herennium Libri IV (contemporary with Cicero but wrongly attributed to him in the middle ages) and Quintilian's Institutio Oratoria.