Invective was often a crucial factor in an orator’s success, whether he was speaking in a judicial prosecution or defense or a political battle fought in the senate or popular assembly (contio). This is because the highlighting of an individual’s faults in an abusive or humorous manner provided a powerful means of manipulating the audience’s emotions. Rather than supplying logical proofs, invective adds pathos to logos and turns the audience against the orator’s opponent and toward his own cause (cf. Cic. Part. Or. 71). As Antonius states bluntly in De Oratore, after winning the attention of his listeners, nothing is more important for the orator than to manipulate their emotions:
Plura enim multo homines iudicant odio aut amore aut cupiditate aut iracundia aut dolore aut laetitia aut spe aut timore aut errore aut aliqua permotione mentis, quam veritate aut praescripto aut iuris norma aliqua aut iudici formula aut legibus. (Cicero, De Oratore 2.178)
For men decide on the majority of issues far more on the basis of hatred or affection or partiality or anger or grief or joy or hope or fear or delusion or some other emotional impulse, rather than on the truth or an objective rule, whether some legal standard or a formula for a trial or the laws.
Humorous invective was one of the most important ways of manipulating the audience’s feelings (cf. Quint. Inst. 10.1.107). For laughter strengthens the orator’s case by winning the favor and admiration of the audience, and by showing him to be a man of polish (Cic. De Or. 2.236). It also hampers the opponent’s argument, trivializes his cause, and can even deter him from speaking. The effect of humorous invective is thus twofold: it denigrates the opponent while simultaneously asserting the speaker’s superiority. Cicero was famous for his witticisms during his own lifetime when at least three collections of his sayings were in circulation (see chapter 16; Cic. Fam. 7.32, 15.21.2; Quint. Inst. 6.3.5; Macrob. Sat. 2.1.12; cf. Plut. Cic. 26-7).