Much verse fails of being poetry because it was not written exactly at the right crisis, though it may have been inconceivably near to it. It is only by a miracle that poetry is written at all. It is not recoverable thought, but a hue caught from a vaster receding thought.
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. 350, Houghton Mifflin (1906).