Man has been here 32,000 years. That it took a hundred million years to prepare the world for him is proof that that is what it was done for. I suppose it is, I dunno. If the Eiffel Tower were now representing the world's age, the skin of paint on the pinnacle-knob at its summit would represent man's share of that age; and anybody would perceive that the skin was what the tower was built for. I reckon they would, I dunno.

Was the World Made for Man? (1903): also p. 106, What is man?: and other philosophical writings, Volume 19 of Works, 1993, Mark Twain, Paul Baender, University of California Press.