Thoreau uses an astonishing range of metaphors to characterize the spiritual quest. Walden Pond itself, where Thoreau's own journey unfolds, is both real and symbolic. It represents the reality of nature, an expression of the divine, human potential for clear perception and understanding, and the mystery of the universe, which, although vast, may nevertheless be approached and understood. Thoreau's bean-field symbolizes the author's inner field, which must be planted, hoed, and tended. Others cultivate themselves by studying art in Boston or Rome, but Thoreau's Transcendental self-culture takes place in the bean-field. Described in "House-Warming" as "an independent structure, standing on the ground and rising through the house to the heavens," Thoreau's chimney symbolizes individual aspiration toward the spiritual and infinite. As it dives into Walden's depths, the loon that shows up repeatedly in the book stands for man in search of higher understanding. The imagery of morning and light in Walden suggests increased perception, insight, and inspiration. And the sand foliage in "Spring" represents the work of the creator, evident to man through nature.
Thoreau presents the spiritual journey of Walden in relation to the cycle of the seasons. The book is structured around the advancing seasons of a single year, beginning with the author's preparing to build his house in the spring, proceeding through fall and winter, and ending with the return of spring. The two years of his actual stay at Walden are compressed into a single year to provide narrative coherence and movement and to build toward the presentation of rebirth in "Spring." The narrator expresses optimism and anxiety at different phases of his spiritual journey. His mood is integrally connected to season. Winter, a time of spiritual dormancy, slows the journey. At the beginning of "The Pond in Winter," he awakens in a state of anxiety, with "the impression that some question has been put to me, which I have been endeavoring in vain to answer in my sleep." If winter delays the processes of perception and understanding, the arrival of spring brings celebration of the divine in nature, exuberant reawakening of all the narrator's faculties, and a renewed sense of spiritual possibility.
