Chris McCandless was an admirer of Henry David Thoreau, and adopted many of the writer's ideals in his own life. He sought simplicity in his own life and tried to live without adhering to material goods and societal norms. Chris also believed that people were meant to "find themselves" through deliberate solitude, and so took steps to live apart from others, even when he shared their ideals. Thoreau's opus Walden was one of the books that Chris took to Alaska.
Unlike... Thoreau, McCandless went into the wilderness not primarily to ponder nature or the world at large but, rather, to explore the inner country of his own soul. He soon discovered, however, what... Thoreau already knew: An extended stay in the wilderness inevitably directs one's attention outward as much as inward...
(Krakauer, Into the Wild, Amazon.com)
Chris took his simple life more seriously than Thoreau had, deliberately placing himself in an environment where no other people could come to help him; this turned out to be his downfall. Thoreau's Walden Pond was within walking distance of a town; while there were habitations around Chris's bus, there was no one living in them, and with the river high, there was no traffic to find his final notes pleading for help. In this manner, Chris took Thoreau's ideals to a self-destructive level; Thoreau advocated simple living, but not in a foolish and unprepared manner.
As noted above, Thoreau, and especially Walden, was intimately woven, as was Tolstoy, into McCandless's emotional life and his quest to strip away the superficial trappings of society and arrive at the essential. Thoreau gave him encouragement and intellectual ballast in his struggle against his father and his father's materialism, which Chris understood as a source of control and coercion.
After Chris killed the moose in Alaska and castigated himself for his inability to preserve it, calling it one of the great tragedies of his life when maggots attacked the carcass, meaning he had "wasted a life" for no good reason, he leaned into and drew comfort from Thoreau. After reading a chapter in Walden on eating, called "Higher Laws," McCandless marked the passage in which Thoreau explained his aversion to meat and called for eating the simplest of diets. Thoreau wrote: "Put an extra condiment into your dish, and it will poison you."
Chris responded to Thoreau's thoughts on food by writing an enthusiastic "YES" in his journal. "Holy food," he wrote, and later, "I am reborn."
The food story provides an example of how Thoreau, in intimate and day-to-day ways, became a father figure and guide, offering inspiration, solace and meaning to McCandless.