"It is so rare to meet with a man outdoors who cherishes a worthy thought in his mind, which is independent of the labor of his hands. Behind every man's busy-ness there should be a level of undisturbed serenity and industry, as within the reef encircling a coral isle there is always an expanse of still water, where the depositions are going on which will finally raise it above the surface."

Source: Henry David Thoreau (2017). “Journeys, Adventures & Life in Harmony with Nature – 6 Book Collection (Illustrated): Including Walden, A Week on the Concord and Merrimack Rivers, The Maine Woods, Cape Cod, A Yankee in Canada & Canoeing in the Wilderness - North American Highlands Series”, p.269, e-artnow