This is how I end my review of Matt Ridley's The Rational Optimist. I defended it from some of the charges against it by William Easterly.
And a book that "only" shows us how economic freedom makes most Americans and many people in other countries wealthier in important respects than John D. Rockefeller, a book that "only" shows that we can have somewhat higher population and higher living standards for most of the world, a book that "only" tells us how to have both more food and more land for wilderness, a book that "only" offsets the dreary, people-hating pessimism that is all around us and is now even in the mind of the White House science adviser? That is not worth a lot? Psshaw. But I will end by letting Ridley answer. He writes:
It is precisely because there is still far more suffering and scarcity in the world than I or anybody else with a heart would wish that ambitious optimism is morally mandatory.