Full Idea
Rhetoric is an agent of the kind of persuasion which is designed to produce conviction, but not to educate people about right and wrong.
Gist of Idea
Rhetoric can produce conviction, but not educate people about right and wrong
Source
Plato (Gorgias [c.378 BCE], 455a)
Book Reference
Plato: 'Gorgias', ed/tr. Waterfield,Robin [OUP World's Classics 1994], p.17
A Reaction
Surely there must be good rhetoric (or at least it is an open question)?