" Sometimes, feeling that his own eloquence is inadequate to the task at hand, the author bows out gracefully and lets his character come across a poem, an Ayn Rand novel, or a quote from Martin Luther King’s “I Have a Dream” speech to spell out the message for him. But the reader is not buying your book to find out what Ani DiFranco has to say about life. She expects you to have something to say about life, and to say it, because that is what we pay writers to do. There are instances when quotes can work very well. These include plots that are in some way about music, poetry, etc., and where there is an interweaving between these and the characters’ lives. Quotes can also work where the quoted material isn’t stating the message but expanding or commenting on it obliquely, so the reader doesn’t feel as if she’s hearing a public service announcement "

― Howard Mittelmark , How Not to Write a Novel: 200 Classic Mistakes and How to Avoid Them—A Misstep-by-Misstep Guide