There is in my nature, methinks, a singular yearning toward all wildness.
(Henry David Thoreau (1817-1862), U.S. philosopher, author, naturalist. A Week on the Concord and Merrimack Rivers (1849), in The Writings of Henry David Thoreau, vol. 1, p. 54, Houghton Mifflin (1906).)
Philosophically considered, the universe is composed of Nature and the Soul.
(Ralph Waldo Emerson (1803-1882), U.S. essayist, poet, philosopher. Nature, Introduction (1836, revised and repr. 1849).
Emerson goes on to explain that by "nature" he means everything that is "not me," hence not only the trees and the sun and the moon, but other people, art, as well as one's own body. This formulation with its Cartesian echoes becomes articulated in more acrimonious (and ironic) terms in the essay "Self-Reliance," when Emerson writes: "Man is timid and apologetic; he is no longer upright; he dares not say 'I think,' 'I am,' but quotes some saint or sage." The saint or sage is, of course, Descartes.)