PPT Slide
Ancient & Medieval Philosophy -- David L. Rouse
That persuasion, when added to speech, can also make any impression it wishes on the soul, can be shown, firstly, from the arguments of the meteorologists, who by removing one opinion and implanting another, cause what is incredible and invisible to appear before the eyes of the mind; secondly, from legal contests, in which a speech can sway and persuade a crowd, by the skill of its composition, not by the truth of its statements; thirdly, from the philosophical debates, in which quickness of thought is shown easily altering opinion.