Charles Murray did a statistical analysis of humankind’s greatest accomplishments in history. “According to his statistics, a whopping 72 percent of the significant figures in the arts and sciences between 1400 and 1950 came from just four European countries: Britain, France, Germany and Italy. But after weighing a number of possible explanations, including the effects of war, civil unrest, economic growth, cities and political freedom on achievement rates, Mr. Murray still was not satisfied. Why, he wondered, when he factored in population growth, did the achievement rate in Europe appear to plummet beginning in the mid-19th century, a period when peace, prosperity, cities and political freedom were steadily increasing?”