Thoeau advocated simpler living in the wilderness, where he believed that Man could come to terms with his own existence and find a higher purpose. London wrote about the powerful, individualistic men who worked in harsh, Northern climates. Tolstoy advocated a life of poverty instead of glorifying wealth. Chris McCandless read and admired all these writers, and imitated some of their ideals in his own life:
Long captivated by the writing of Leo Tolstoy, McCandless particularly admired how the great novelist had forsaken a life of wealth and privilege to wander among the destitute. In college McCandless began emulating Tolstoy's asceticism and moral rigor...
(Krakauer, Into the Wild, Amazon.com)
Tolstoy was perhaps the largest influence on Chris, who also came from a well-off family and did not need to live in poverty; his choice to abandon his old life and seek a simpler one was in pursuit of his own ideals and dreams, which were shaped by the above authors as well as many others. His passion for living alone in the wilderness was influenced by Thoreau, and his desire to pit himself against the harshness of Alaska came from London's stirring adventure stories. Each author added to Chris's personal philosophies, and he followed their examples as much as he was able.
They all supported McCandless's passion to live a lifestyle of freedom and complete self reliance. They glorified nature and put almost in the place of a religion. They were all famous transcendentalists.