in Thoreau’s Journal:

After having some business dealings with men—I am occasionally chagrined—& feel as if I had done some wrong—& it is hard to forget the ugly circumstance— I see that such intercourse long continued would make me thoroughly prosaic hard & coarse— But the longest intercourse with Nature though in her rudest moods does not thus harden & make coarse— A hard insensible man whom we liken to a rock—is indeed much harder than a rock—

From hard coarse insensible men with whom I have no sympathy—I go to commune with the rocks whose hearts are comparatively soft—