Transcendentalism is an American literary, political, and philosophical movement of the early nineteenth century, centered around Ralph Waldo Emerson. Other important transcendentalists were Henry David Thoreau, Margaret Fuller, Amos Bronson Alcott, Frederic Henry Hedge, and Theodore Parker. Stimulated by English and German Romanticism, the Biblical criticism of Herder and Schleiermacher, and the skepticism of Hume, the transcendentalists operated with the sense that a new era was at hand. They were critics of their contemporary society for its unthinking conformity, and urged that each person find, in Emerson's words, “an original relation to the universe” (O, 3). Emerson and Thoreau sought this relation in solitude amidst nature, and in their writing. By the 1840s they, along with other transcendentalists, were engaged in the social experiments of Brook Farm, Fruitlands, and Walden; and, by the 1850s in an increasingly urgent critique of American slavery.