Question

Theroux points out that visiting a once-great city that is now in ruins gives "perspective" on "human effort"
Source: Riding the Iron Rooster by Paul Theroux, page 199. Published by Mariner Books, New York 1988:
Nothing puts human effort into better perspective than a ruined city. "This was once a great capital," people say, pointing to the fallen walls and broken streets and dust.

Answer 1

"These ruins are evidence of how much energy and labor have been expended - sometimes wasted - on building. And this is what people have to show for it: tumbling stones, disintegrating walls, empty streets. It's a sobering reminder of the impermanence of human achievement."