Across the track, a rail yard worker big innocent bear of a guy, beer belly, embraces his girl. She’s a conductor, comes up to that belly, reaches arms not quite around his back. They separate and embrace three times while the train prepares for departure. Across the aisle, a mother and son. Lights out, change engines, they play Mercy. Squeeze fingers until one cries mercy. The son still too small to seriously challenge his young, athletic mom. Ask and answer questions, laugh and cry mercy, she draws and he colors the features. Unless a society expects its fate to be better than its past, it will strive to make its present immutable as possible. Optimism is a way of exploring failure. It says there is no law of nature or supernatural decree preventing progress. Nearly all failures, and all successes, are in our future.
—Deutsch, David, The Beginning of Infinity, Viking Press, 2011.