The slumbering of mankind and need for spiritual awakening
To Thoreau, the trappings of nineteenth century existence the cycle of tiring work to support property ownership forced the common man to live as if he were sleep-walking. Thoreau uses the idea of slumbering as a metaphor for mankind's propensity to live by routine, without considering the greater questions and meaning of existence. Therefore, Thoreau urges his readers to seek a spiritual awakening. He emphasizes the perspective he gains by awakening early and experiencing nature while others in the village are still sleeping and using the metaphor of awakening in the morning to demonstrate the difference between himself and his Concord townsmen. The spiritual awakening of Thoreau and his readers is reflected both in the times of day and in the seasons of the year, with the greatest self-awareness and spiritual discoveries occurring in the morning and spring.
Man as part of nature
Living in a society in which man in the form of railroads, factories, and other technical innovations had begun to tame and control nature, Thoreau counters the separation of man from society by conceiving of man as a part of nature. Through his life in the woods, living for the most part off the fruits of the land and deriving intellectual stimulation from plants and animals, Thoreau demonstrates that man can live successfully in the midst of nature. The animals give him companionship and accept him as a familiar part of their environment. Even nature itself is empathetic to him, for example waiting to blow its coldest winds after Thoreau builds his chimney and plasters his walls. The assertion that man is part of nature promotes Thoreau's suggestion that most people who be more intellectually fulfilled and spiritually aware away from the smothering cocoons of city and village life.
The destructive force of industrial progress
Thoreau began his life at Walden, when the Industrial Revolution was in full force. Its impact upon life is best illustrated in Walden by the locomotive which passes daily by the pond, its whistles and rumbling contrasting with the natural sounds of the birds. Village life now runs at a faster pace, "railroad time," leaving even less time for the contemplation of self and nature which Thoreau desires. Such "progress" has a negative impact upon people's lives and upon the environment, the purity of which it pollutes and destroys.
The animal/spiritual dialectical struggle within man
Within himself and all men, Thoreau perceives two struggling natures one a wild, animal nature and the other a spiritual nature. It is this animal nature which occasions the impulse to catch and deliver a woodchuck raw and which he detects in its fullest form in the French-Canadian woodcutter. However, he seeks in himself and urges in his reader the perfection of the spiritual nature, through avoidance of meat and animalistic desires, and represents the struggle in himself through the imagined conversation between the Hermit (spiritual) and Poet (animal). Only within a few examples from the animal kingdom noble battling ants, the winged cat, and the loon can Thoreau see the animal and spiritual coexist peacefully.
Nature as reflection of human emotions
More than once, Thoreau describes Walden Pond as a mirror. Throughout the novel, the weather continually reflects his emotional state. His period of melancholy and doubt occurs during the winter when the pond is frozen and nature is silenced, and his joy and exultation is reflected in the thawing of the lake and growth of new life in the spring. The daily and seasonal variations in the pond and surrounding environment parallel the variety of and changes in Thoreau's intellectual musings. The idea of nature reflecting human emotion supports Thoreau's belief in man as a part of, rather than separate from or above, nature.
Spiritual rebirth reflected in nature and the seasons
Thoreau employs the repeated metaphor of rebirth throughout his book, as a means of convincing his readers to seek new perspective on themselves and the world. The cycle of the seasons, with the rebirth of the winter-dormant pond, animals, and plants in the spring, functions as the promise of an eventual spiritual rebirth in humans. Likewise, Thoreau's description of the hunter boy who grows to be a naturalist as a man and his metaphor of awakening from the slumber of life evince his hope and belief in the progress of human beings to a newer, greater understanding of themselves. He ends the book with a final metaphor of rebirth, describing the bug which hatched out of a wooden table after decades, in the hope that some day, even if not immediately such a rebirth will occur within human society.
Discovery of the essential through a life of simplicity
In his first chapter, "Economy," Thoreau says that he went to the woods to describe what is truly necessary in life. Later, he says that he "went to the woods to live deliberately" so that when he died he would not find that he had never really lived. By ridding himself of the luxuries of society a big house, coffee, meat, even salt and yeast Thoreau discovers through his own "economy" what is really necessary to live a fulfilled life. His discovery of the relatively small amount of work needed to live in relative comfort leads him to attempt to convince his reader as well as John Field to similarly simplify their own lives and thus live more happily. For Thoreau, this is a happy discovery, for he comes to believe that one could be as happy in almshouse, with the same afternoon sun coming in the window as does in a rich person's house, as he would anywhere else. To his reader, Thoreau insists, "Simplicity! Simplicity! Simplicity!"
Exploring the interior of oneself
Thoreau omitted the subtitle of Walden, or Life in the Woods in its subsequent publications because he feared his readers would take it too literally. Though he was enthralled by the nature around him, Thoreau also went to the woods to consider himself. In his final chapter, he urges his reader, who may not be able to voyage to Africa or India, to instead explore within himself. He believes that there are uncharted depths within such as will continue to surprise and occupy anyone who explores within, but he perceives that such self-exploration is rare. He uses his own experience at Walden as an example for his reader and urges not social change but change on the level of the individual.
The Transcendentalist conception of nature as the embodiment of the divine
A follower of the Concord school of Transcendentalism and a good friend of Ralph Waldo Emerson, Thoreau expressed and clarified his own personal understanding of Transcendentalism in Walden. For him, the divine is most sublimely expressed in nature. He draws upon various Christian conceptions of the divine, as well as those from Eastern religions with which he is familiar, and recontextualizes them to create new meaning. For him, the role of God as creator of all of nature is most inspirational, and through this understanding, he expresses the Transcendentalist belief in existence of a spark of divinity in all men.
The state as unjust and corrupt controller of men's thoughts and actions
In sentiments that would be more fully expressed in his essay "Civil Disobedience," Thoreau recounts in Walden the story of his imprisonment in jail for not paying taxes to a government that supports slavery. Elsewhere in the book, as when aids a fugitive slave on his journey to Canada, Thoreau demonstrates his opposition to slavery and disgust with the Fugitive Slave Law. He sees the state and its institutions as corrupt and insidious controllers of men, even when they try to escape it, as he does by living in the woods. On a more basic level, he sees the gossip of townspeople and the constant, artificial interactions demanded by village life as distracting from concentration on the true essentials of life.
