Persuasion is clearly a sort of demonstration, since we are most fully persuaded when we consider a thing to have been demonstrated. Of the modes of persuasion furnished by the spoken word there are three kinds. ... Persuasion is achieved by the speaker"s personal character when the speech is so spoken as to make us think him credible. ... Secondly, persuasion may come through the hearers, when the speech stirs their emotions. ... Thirdly, persuasion is effected through the speech itself when we have proved a truth or an apparent truth by means of the persuasive arguments suitable to the case in question.
~Aristotle