The message about human betterment and economic progress is more general than any individual statements about raw materials, air, water, life expectancy, education, and the like. There is solid theoretical basis for the idea that that all aspects of human welfare should get better, not just as a matter of coincidence but as part of a broad causal mechanism. Humanity has necessarily evolved so that we have more of the nature of creators than of destroyers—or else the species would have died out long ago. People seek to improve their conditions, and therefore on balance people build more than they tear down and produce more than they consume. Hence each generation leaves the world a bit better in most respects than it begins with.