SCITHERO. Marcus Tullius Cicero, 106-43 B.C., was one of the greatest Roman orators and statesmen. His speeches as a lawyer show every kind of rhetorical device and a variety of literary styles. The most important of his works, which greatly influenced medieval writers, especially Jerome, Ambrose, and Augustine, are De oratore (On Oratory), De re publica (On Public Matters, of which Book Six is the famous In somnium Scipionis [On Scipio's Dream]), De officiis (On Offices), De senectute (On Old Age), and De amicitia (On Friendship), and several volumes of letters to his friends. One work, Rhetorica ad herennium, written by one Cornificius (fl. 86-82 B.C.), was attributed to Cicero during the medieval period and greatly influenced the rhetoricians of the period, Geoffrey de Vinsauf and Matthew of Vendome, whose works Chaucer knew and used frequently.
Chaucer's references to "colours of rhetoric" and "figures," ClT 16; FranklT 722, are terms appropriated from Rhetorica ad herennium. The Franklin says that he has not slept on Parnassus nor learned Marcus Tullius Scithero, FranklT 721-722. [Tullius1]
The peculiar spelling Cithero, a variant of Cicero, the family name, has been found in manuscripts dated before and during the fourteenth century and may account for Chaucer's Scithero. It is also found in Walter Map's Dissuassio Valerii ad Rufinus philosophum ne uxorem ducat (1181-1183). The name appears in final rhyming position, FranklT 722.