Themes are the fundamental and often universal ideas explored in a literary work.
Christopher McCandless wants to be perfectly self-reliant. He quests for this ideal independence and isolation, but it escapes him at every turn. The sheer number of interviews included in the book testifies to how many people helped McCandless at the same time he claimed he wanted to leave everyone behind. Nowhere is the illusory nature of McCandless’s self-reliance more clear, however, than when McCandless heads down the Stampede Trail in what is to be the last trip of his life. McCandless decides to remain in an abandoned bus instead of making a shelter of his own. The pre-existing structure, which is kept in good condition by hunters, proves too convenient to pass up. Perhaps most significantly, McCandless cannot save his own life when he becomes too weak to forage. If he had not decided to leave human contact behind entirely, he might have been able to receive help.
The unconquerable, unpredictable side of nature appears in the first pages of Into the Wild and continues to appear throughout the book. Alaska residents, for instance, insist that people like Christopher McCandless are fools to approach the wild with the idea that its vast beauty will solve their emotional or spiritual difficulties. No plan laid by any of the book’s explorers seems to succeed. Nature confounds nearly all of them. In his personal narrative, Krakauer stresses that he was unspeakably lucky to have survived his attempt to summit the Devils Thumb glacier, because of storm conditions he could not have foreseen. McCandless studies his edible plant guide and makes no mistakes in identifying species he can use to supplement his diet. He succumbs, however, to a mold growing on a seed he thought was safe to eat. A flooded river blocks his way when he decides he wants to head back to civilization. Many of the book’s events, including its final outcome, reflect the tragic irony of the idea that nature can be controlled. Too much of nature is both invisible and too unpredictable for McCandless to survive.
Christopher McCandless rejects his father, but the same qualities he hates in Walt McCandless reappear in his own decision to head into the wild. McCandless found his father overbearing, but at the same time, he frequently lectures his own parents. He also persuades vulnerable people, including his friend Ronald Franz, to take up his self-reliant, tramper’s philosophy as their own. Perhaps most importantly, McCandless is angered at his father’s secret family. He maintains that Walt McCandless lets him and his sister live in ignorance. He then keeps his own location secret from his family. This mirroring of his father’s behavior links Christopher McCandless to Walt McCandless and demonstrates a likeness between them precisely where Christopher might have least wanted to see it. In addition, the narrator explicitly ties his own childhood recklessness to his father’s influence.