Epigraphs are like little appetizers to the great main dish of a story. They illuminate important aspects of the story, and they get us headed in the right direction.
"Tis very strange Men should be so fond of being thought wickeder than they are."
– Daniel Defoe, A System of Magick
"In historical events great men – so called – are but the labels that serve to give a name to an event, and like labels, they have the last possible connection with the event itself. Every action of theirs, that seems to them an act of their own free will, is in an historical sense not free at all, but in bondage to the whole course of previous history, and predestined from all eternity."
– Leo Tolstoy, War and Peace
"Well," said the Head, "I will give you my answer. You have no right to expect me to send you back to Kansas unless you do something for me in return. In this country everyone must pay for everything he gets. If you wish me to use my magic power to send you home again you must do something for me first. Help me and I will help you."
"What must I do?" asked the girl.
"Kill the Wicked Witch of the West," answered Oz.
– L. Frank Baum, The Wonderful Wizard of Oz
We get three epigraphs for the price of one here. Our first epigraph is a quote from Daniel Defoe, who was a British essayist, novelist, and playwright in eighteenth century England. Defoe is probably most famous for having written Robinson Crusoe (1719). But he also wrote hundreds of essays on a diverse range of topics, from politics to religion to, believe it or not, magic. Defoe was actually quite interested in magic, witches, the occult, and their history in England. He was especially interested in how magic and religion interacted. (If the witch trials are anything to go by, not well.)
The quote we get from Defoe talks about how people like having others think certain things about them that aren't necessarily true. Some people even get a kick out of being thought of as "wicked," which isn't too surprising. After all, isn't an evil mastermind cooler than a boring, everyday Joe Shmo?
So why might this quote appear at the beginning of a story about the Wicked Witch of the West? Well, it gives us a major clue as to what Wicked is going to be about: reputation and appearance. Through Defoe, Maguire is suggesting upfront that maybe his Wicked Witch (Elphaba) is not nearly as wicked as people think. It's also notable that Defoe emphasizes people's positive reaction to being thought wicked. In Maguire's novel, Elphaba has a very complicated relationship with her own bad reputation, and Defoe's quote is something to keep in mind when exploring her complex character.
Our second epigraph comes from a Russian novelist, Leo Tolstoy, in his novel to end all novels, War and Peace. War and Peace is (basically) about Napoleon invading Russia back in 1812. (The novel itself was published in 1869.) Fun historical fact: this may have been Napoleon's worst idea ever, since he got completely creamed by the horror that is winter in Russia.
There's a ton going on in War and Peace, but for our purposes we just need to focus on one major theme: history. Tolstoy was hugely interested in history: how it was written, how people remembered it, who "made" it, etc. He spent a lot of time engaging with the ideas of G.W.F. Hegel, a German historical philosopher who would one day inspire Karl Marx.
Hegel came up with the idea of historical determinism, which is a fancy way of saying that history sweeps people along for the ride. So Columbus didn't just sail the ocean blue in 1492; rather, a whole confluence of circumstances and events, from Spain's economy to the dudes who built the fleet of ships, conspired to get Columbus on board and across the Atlantic. Columbus the individual didn't have that much to do with it.
The epigraph here suggests that people are kind of "slaves" to history, which has been "predestined." History can only play out one way, and individual people, particularly so-called "great" or powerful people, have very little to do with how history goes. These ideas are hugely important in Wicked, which is all about how one green woman becomes a famous and world-changing figure without even really trying.
Throughout the novel, we get hints that Elphaba isn't in control of her destiny and that her eventual fate, to become the Wicked Witch of the West and die at the hands of Dorothy, was predetermined. History here acts the same way as prophecy. Elphaba herself often worries about how she's not in control of her life, and Tolstoy's thoughts on how history controls people more than they control it helps highlight these ideas in Wicked.
Our final epigraph is fittingly from the book that started everything: The Wonderful Wizard of Oz. Here we get the dialogue from the scene where the Wizard tasks Dorothy with killing the Wicked Witch of the West. But it's also important that Baum's scene casts Oz as a sort of magical free-capitalist land (Ayn Rand would be stoked). The Wizard points out that Oz is a quid-pro-quo society and that Dorothy has to do something for him before he'll do something for her.
Maguire's book doesn't really go off on capitalism, but it does explore themes of power and corruption. This epigraph, which emphasizes how the Wizard shrewdly trades favors instead of just doing them out of the goodness of his heart, sets up the Wizard as a sort of savvy politico, which is a major part of his character in the world of Wicked.
Taken together, these three epigraphs work to establish some of the book's most important themes: perception and reputation, history and destiny, and power and corruption. Importantly, all of these themes act together to form the person we're all here to read about: The Wicked Witch of the West.