How golden ages really start – and end

Peak Human By Johan Norberg. Atlantic Books; 400 pages; US$32.99 and £22

THE way to start a “golden age” is to erect big, beautiful barriers to keep out foreign goods and people. That, at least, is the view of the most powerful man on the planet. Johan Norberg, a Swedish historian, makes the opposite case. In Peak Human, Norberg charts the rise and fall of golden ages around the world over the past three millennia, ranging from Athens to the Anglosphere via the Abbasid caliphate. He finds that the polities that outshone their peers did so because they were more open – to trade, to strangers and to ideas that discomfited the mighty. When they closed up again, they lost their shine.

Consider the Song dynasty in China, which lasted from 960 to 1279AD. Song emperors were much keener on the rule of law than their predecessors, who tended to rule by whim. To enforce predictable rules, they hired lots of officials via meritocratic exams. The first Song emperor enacted the “unconventional policy reform” of “(not) killing officials who disagreed with him”.