QUOTE : What the economist and historian Deirdre N. McCloskey calls the Great Enrichment began in seventeenth-century Holland, gathered steam—literally—in eighteenth-century Britain and the American colonies. Although agriculture was invented about 11,000 years ago, it took 4,000 years for it to supplant hunting and gathering as mankind’s main source of food. This made possible the rise of cities, which involved transactions that led to the development of writing about 5,000 years ago and mathematics about 4,000 years ago. But modernity means velocity. It took 4,000 years for mankind to adapt harnesses to the long necks of horses. But just sixty-six years after the Wright brothers’ first flight, which covered a distance shorter than the wingspan of a Boeing 747, a man walked on the moon.