There is no necessity for the man who means to be an orator to understand what is really just but only what would appear so to the majority of those who will give judgment; and not what is really good or beautiful but whatever will appear so; because persuasion comes from that and not from the truth.
persuasionquotes
There are, then, these three means of effecting persuasion. The man who is to be in command of them must, it is clear, be able (1) to reason logically, (2) to understand human character and goodness in their various forms, and (3) to understand the emotions-that is, to name them and describe them, to know their causes and the way in which they are excited.
character / emotions / persuasion / reason