Walter Tevis, The Man Who Fell to Earth

"Do you realize that you will not only wreck your civilization, such as it is, and kill most of your people; but that you will also poison the fish in your rivers, the squirrels in your trees, the flocks of birds, the soil, the water? There are times when you seem, to us, like apes loose in a museum, carrying knives, slashing the canvases, breaking the statuary with hammers."