Nature is a short book, an essay, by Ralph Waldo Emerson. He developed it from his early lectures and published in 1836. In it, he sets the foundation, which is the main principles of transcendentalism, postulating the need for "an original relation to the universe" and rejecting time worn attitudes to God and Nature.
Nature, as defined by Emerson, is an all-encompassing divine entity, rather than as a component of a world ruled by a divine, learned by us through passed on teachings.
Transcendentalism opposes the idea that man needs an intercessor to get to God; it is also critical of a formalized religion. Some advocates of transcendentalism, aside from Ralph Waldo Emerson, are Henry David Thoreau, Margaret Fuller and Bronson Alcott.
Emerson elaborates his conception of nature as the expression of a divine will. Man has to assert himself in order to establish a relationship with nature that will allow him to make use of spiritual self-governance. In so doing, he unites himself with the source of his spirituality.