The work of a shy, studious bachelor in his early 50s, the book ran to almost 1,100 pages. It was “An Inquiry into the Nature and Causes of the Wealth of Nations,” by Scottish polymath Adam Smith.

But with this urgency comes social and environmental risks, including a hidden mental-health crisis that experts say is likely to get worse. My brother died by suicide in 2022, just shy of his 40th ...