Aristotle had a lot to say about persuasion in his day. Much of what he thought about it is in lecture notes called "On Rhetoric." Public speaking experts begin with Aristotle and his famous triad of Logos, Ethos, and Pathos. Because he believed public speaking was central to democracy as he understood it, he was intent on distinguishing persuasion from flattery, lying, and propaganda. Today we need his viewpoint more than ever.