4 ideas
Cicero holds that the orator must do three things: teach or prove (docere), delight or win goodwill (delectare/conciliare), and move the emotions (movere). Proof secures the audience's understanding, charm keeps them receptive to the speaker, and emotional force is what finally turns their judgment.
Cicero divides the orator's work into invention (finding the arguments), arrangement (ordering them), style (clothing them in words), memory (holding the speech in mind), and delivery (voice, face, and gesture). Each stage is a distinct skill with its own techniques. Treating preparation as this sequence stops a speaker from polishing phrasing before settling what to argue and in what order.
Cicero treats propriety (decorum) as the governing rule of eloquence. The plain, middle, and grand styles are each correct only when matched to the subject, the audience, the moment, and the speaker's own standing. Grand, emotional language used on a trivial matter looks absurd, and a flat tone used on a grave matter looks indifferent, so the same words can persuade in one setting and backfire in another.
Cicero argues that audiences decide more through feeling and through their impression of the speaker than through facts or legal rules. The orator should therefore build goodwill by presenting his own character, and his client's, as trustworthy. At the decisive moment he should stir anger, pity, or indignation, and he must visibly feel these emotions himself, because a speaker who is unmoved cannot move others.