昆提连（公元1世纪罗马雄辩家）称演讲家是“一个精于讲话的好人”。他指的是真诚和信心。本书已经说过和将要说的一切，没有一个能取代这个必要的条件。以尔旁·摩根说，信心是获取信任的最好方法，同时也是获得听众信心的最好方法。Quintilian described the orator as "a good man skilled in speaking". He was talking about sincerity and character. Nothing said in this book, nor anything which will be said, can take the place of this essential attribute of speaking effectiveness. Pierpont Morgan said that character was the best way to obtain credit; it is also the best way to win the confidence of the audience.

“一个人说话时的那种真诚，”亚历山大·伍柯特说，“会让他的声音焕发出真实的光彩，那是虚伪的人假装不了的。”The sincerity with which a man speaks, said Alexander Woolcott, "imparts to his voice a color of truth no perjurer can feign."

如果我们的目的是说服别人，特别需要发自真诚和自信的内在光辉来宣讲自己的理念。我们自己先被说服，然后才能设法说服别人。Especially when the purpose of our talk is to convince, it is necessary to set forth our own ideas with the inner glow that comes from sincere conviction. We must first be convinced before we attempt to convince others.