Walden opens with a simple announcement that Thoreau spent two years in Walden Pond, near Concord, Massachusetts, living a simple life supported by no one. He says that he now resides among the civilized again; the episode was clearly both experimental and temporary. The first chapter, “Economy,” is a manifesto of social thought and meditations on domestic management, and in it Thoreau sketches out his ideals as he describes his pond project. He devotes attention to the skepticism and wonderment with which townspeople had greeted news of his project, and he defends himself from their views that society is the only place to live. He recounts the circumstances of his move to Walden Pond, along with a detailed account of the steps he took to construct his rustic habitation and the methods by which he supported himself in the course of his wilderness experiment. It is a chapter full of facts, figures, and practical advice, but also offers big ideas about the claims of individualism versus social existence, all interspersed with evidence of scholarship and a propensity for humor.

Thoreau tells us that he completed his cabin in the spring of 1845 and moved in on July 4 of that year. Most of the materials and tools he used to build his home he borrowed or scrounged from previous sites. The land he squats on belongs to his friend Ralph Waldo Emerson; he details a cost-analysis of the entire construction project. In order to make a little money, Thoreau cultivates a modest bean-field, a job that tends to occupy his mornings. He reserves his afternoons and evenings for contemplation, reading, and walking about the countryside. Endorsing the values of austerity, simplicity, and solitude, Thoreau consistently emphasizes the minimalism of his lifestyle and the contentment to be derived from it. He repeatedly contrasts his own freedom with the imprisonment of others who devote their lives to material prosperity.

Despite his isolation, Thoreau feels the presence of society surrounding him. The Fitchburg Railroad rushes past Walden Pond, interrupting his reveries and forcing him to contemplate the power of technology. Thoreau also finds occasion to converse with a wide range of other people, such as the occasional peasant farmer, railroad worker, or the odd visitor to Walden. He describes in some detail his association with a Canadian-born woodcutter, Alex Therien, who is grand and sincere in his character, though modest in intellectual attainments. Thoreau makes frequent trips into Concord to seek the society of his longtime friends and to conduct what scattered business the season demands. On one such trip, Thoreau spends a night in jail for refusing to pay a poll tax because, he says, the government supports slavery. Released the next day, Thoreau returns to Walden.

Thoreau devotes great attention to nature, the passing of the seasons, and the creatures with which he shares the woods. He recounts the habits of a panoply of animals, from woodchucks to partridges. Some he endows with a larger meaning, often spiritual or psychological. The hooting loon that plays hide and seek with Thoreau, for instance, becomes a symbol of the playfulness of nature and its divine laughter at human endeavors. Another example of animal symbolism is the full-fledged ant war that Thoreau stumbles upon, prompting him to meditate on human warfare. Thoreau’s interest in animals is not exactly like the naturalist’s or zoologist’s. He does not observe and describe them neutrally and scientifically, but gives them a moral and philosophical significance, as if each has a distinctive lesson to teach him.

As autumn turns to winter, Thoreau begins preparations for the arrival of the cold. He listens to the squirrel, the rabbit, and the fox as they scuttle about gathering food. He watches the migrating birds, and welcomes the pests that infest his cabin as they escape the coming frosts. He prepares his walls with plaster to shut out the wind. By day he makes a study of the snow and ice, giving special attention to the mystic blue ice of Walden Pond, and by night he sits and listens to the wind as it whips and whistles outside his door. Thoreau occasionally sees ice-fishermen come to cut out huge blocks that are shipped off to cities, and contemplates how most of the ice will melt and flow back to Walden Pond. Occasionally Thoreau receives a visit from a friend like William Ellery Channing or Amos Bronson Alcott, but for the most part he is alone. In one chapter, he conjures up visions of earlier residents of Walden Pond long dead and largely forgotten, including poor tradesmen and former slaves. Thoreau prefers to see himself in their company, rather than amid the cultivated and wealthy classes.

As he becomes acquainted with Walden Pond and neighboring ponds, Thoreau wants to map their layout and measure their depths. Thoreau finds that Walden Pond is no more than a hundred feet deep, thereby refuting common folk wisdom that it is bottomless. He meditates on the pond as a symbol of infinity that people need in their lives. Eventually winter gives way to spring, and with a huge crash and roar the ice of Walden Pond begins to melt and hit the shore. In lyric imagery echoing the onset of Judgment Day, Thoreau describes the coming of spring as a vast transformation of the face of the world, a time when all sins are forgiven.

Thoreau announces that his project at the pond is over, and that he returned to civilized life on September 6, 1847. The revitalization of the landscape suggests the restoration of the full powers of the human soul, and Thoreau’s narrative observations give way, in the last chapter of Walden, to a more direct sermonizing about the untapped potential within humanity. In visionary language, Thoreau exhorts us to “meet” our lives and live fully.