Using quotes in your speech could add to the selling power of whatever idea you want your audience to understand and accept. There is a hint of truth in them that their authors, who were inspired enough to make them, wanted to impart to would-be listeners. For example, if you want to talk about happiness, you could use the following quotes to supplement your selling idea:"No man is happy unless he believes he is." - Pubilius SyrusUsing this quote at the start of your speech would introduce the idea the one`s happiness depends on that person`s perspective. You, as the speaker, could expand your idea from here."No man is happy but by comparison." - Thomas ShadwellThis quote would then introduce a problem that the audience would no doubt relate to: how comparison would lead to questioning one`s level of happiness. "If you want to be happy, be." - Leo TolstoyThis quote would then serve sum up the point of t...