Transcendentalism is a literary, philosophical, and cultural movement that began in New England in the mid 19th century. Its theories were espoused and encouraged by writers like Ralph Waldo Emerson and Henry David Thoreau. The ministers Frederick Henry Hedge and Theodore Parker were important transcendentalists, as was Sophia Peabody, Nathaniel Hawthorne’s wife.
The concept is based in theories preceding it. Most influential were the writings of the 18th century philosopher Immanuel Kant, who theorized that the only true knowledge was that which could be known instinctively instead of proved empirically. A vastly important additional influence was the work of the Romantic poets, particularly William Wordsworth and Samuel Taylor Coleridge. Some people refer to transcendentalism as American Romanticism.
Instead of embracing traditional Christian theory, Wordsworth and Coleridge believed that people had an innate sense of the spiritual, a spiritual knowledge that transcended what could be known empirically, or what could be corrupted by the senses. Transcendentalists were also reacting against the spiritual tradition of the Unitarian church, a non-trinitarian form of Christianity. Sometimes, they were also specifically opposed to the theories espoused during the Enlightenment and the Age of Reason.
Unitarians at that time embraced the idea that reason, science, and philosophy helped people to discover the purpose of life and the spiritual world. Those who adopted transcendentalism felt that scholarship directly interfered with innate knowing, and clouded the senses rather than clearing them for personal perception of the divine. The divine was there to be felt rather than something one had to be convinced of. Some straddled the fence on this issue; Emerson was both naturalist and transcendentalist. Many Unitarian ministers became transcendentalists at this time.
The poets and writers associated with this movement especially expressed the sense of awareness that could be had from being “in nature.” This was certainly a direct reflection of the English Romantic movement in poetry. Wordsworth and others specifically celebrated nature as the source of the divine, not just the outdoors and the natural manifestations of earth, but also the essence or nature of the human.
From Emerson’s work Nature the concepts of transcendentalism are well expressed:
"Standing on the bare ground, — my head bathed by the blithe air, and uplifted into infinite space, — all mean egotism vanishes. I become a transparent eye-ball; I am nothing; I see all; the currents of the Universal Being circulate through me; I am part or particle of God."
The sense in Emerson and writers like him is that the natural world allows people to shed the perceptual rational part of themselves, to instead engage actively with the divine.
Another extremely important work related to this movement is Henry David Thoreau’s Walden. The poetry of Walt Whitman, particularly Leaves of Grass, is a vital explanation of the movement. William Cullen Bryant and his master poem “Thanatopsis” are also important.
Another key feature of the movement was its growing respect and value for the position of women. It was out of transcendentalism that women in the United States would begin to campaign for the vote. This movement also embraced a transcendent love of all races, and took up the cause of unjust treatment of Native Americans and slaves. Not every transcendentalist was concerned about these reforms, but many of them used their instincts to listen to the human nature of essential equality, since humans are all, as Emerson said, “part or particle of God.”