Nothing, in my opinion, is more gentle than Nature; once aware of having been seen, she does not again expose herself to the gaze of soul.
 Henry David Thoreau, A Week on the Concord and Merrimack Rivers (1849). copy citation

Context

“But where is the instructed teacher? Where are the normal schools? A Hindoo sage said, “As a dancer, having exhibited herself to the spectator, desists from the dance, so does Nature desist, having manifested herself to soul—. Nothing, in my opinion, is more gentle than Nature; once aware of having been seen, she does not again expose herself to the gaze of soul.” It is easier to discover another such a new world as Columbus did, than to go within one fold of this which we appear to know so well; the land is lost sight of, the compass varies, and mankind mutiny;” source