The most interesting psychological cases in the Chronicles are those who do not remain fixed in character but are profoundly changed by their time in Narnia. Perhaps the best example is Edmund Pevensie, who sinks down to what Dante considered one of the worst of sins--betrayal of kindred--and then recovers in later life so fully that he earns his title, Edmund the Just. By tracing Edmund's fall and rise, readers can see most of the qualities Lewis associated with moral malaise and moral health.
Lucy feels Edmund began to go wrong during his first term at a "horrid school." Lewis used the term "childhood" in all his books to suggest simplicity, wonder, and self-forgetfulness. By contrast, he associated the terms "boyhood" and "school" with a time of life "in which everything (ourselves included) has been greedy, cruel, noisy, and prosaic, in which the imagination has slept." In 1962, nearly a half century after he left them behind, Lewis still described two of the boarding schools he attended (Wynyard and Malvern) as "very horrid" and said he hated them even worse than his time in the trenches of World War I. It is not surprising, then, that when we first meet Edmund in "The Lion, the Witch and the Wardrobe" his time at boarding school has already turned him into a cynic and a bully.
There is very little to like about Edmund in the early pages of "The Lion, the Witch and the Wardrobe." He laughs at Professor Kirke's eccentric looks, snaps at his older sister Susan when she says it's time for bed, and whines about a rainy day. He teases Lucy mercilessly about her "imaginary" world inside the wardrobe, not in fun but out of sheer spite. When Edmund gets into Narnia himself, he is easy prey for the blandishments of the White Witch. Her flattery appeals to his pride and her magical Turkish Delight to his gluttony. And her promise to make him a king appeals to his rebellious instinct to rule his older brother Peter, the natural leader of the family. By the time the evil queen sends Edmund back to his own world, her magic has already found a receptive vessel, and she has found in him a useful new vassal.
Lewis's concept of the central self, affected one way or the other by every moral choice, implies a kind of moral momentum. Every good choice strengthens one's inner resolve to make another good choice next time, while every bad choice leaves one inclined to further bad choices down the road. At first, Edmund is only selfish and ill-tempered. But when he deliberately lies, refusing to confirm Lucy's story and admit there really is a magic world inside the wardrobe, he does great harm to his own soul. Here is falsehood, pride, and spite all bound up together, a sign that Edmund's downward drift has turned into a descent. Lewis wrote that "rebellion of the will" usually leads to "fogging of the intelligence," and Edmund's lie will lead to a whole series of wrong-headed and wrong-hearted choices.