On Plato's Dialogue, "Gorgias" (380 BCE or so). Why philosophize? Isn't it better to know how to persuade people in practical matters, like a successful lawyer or business leader? Plato (via Socrates) thinks that the "art" of rhetoric isn't an art at all, in the sense of requiring an understanding of one's subject matter, but merely a talent for saying what people want to hear. Looking for the full Citizen version?