Historians and others who try to explain the world dominance by the West since the 18th century usually put it down to long-term lock-in or short-term accidents, said Morris. The lock-in theories are belied by the dominance of the East from 550 to 1750 CE. The accidents approach is undermined by clear patterns that emerge when you look for them in a rigorous way.
Morris has devised a quantitative "social development index" based on evaluating a civilization's energy capture, organization (size of largest cities), information management, and war-making capability. (The details of his method are online here.) When you graph human progress since the last ice age 15,000 years ago, the results show that the West led for all the millennia up till the 6th century CE, fell behind for 1,200 years, then leapt ahead again up to the present day. (The "West" for Morris is the civilizational core that developed agriculture and then cities and empires in the eastern Mediterranean, later spreading across Europe and North America. The "East" is China.)
Geography determines how and when regions develop, but new societal capabilities keep redefining what geography means. At first agriculture was limited to regions with reliable rainfall, but once societies grew able to manage large-scale irrigation, the empires of parched regions like Mesopotamia and Egypt could take off, and their rivers became trade routes. The vast steppes of north-central Asia long separated Western and Eastern empires, but once their riches became worth plundering, mounted nomads from the steppes invaded repeatedly, defeating the agrarian armies and carrying germs that unleashed waves of epidemics.
The West had the advantage of a trade highway in the Mediterranean that wasn't matched in the East until the 6th century, when the Sui emperors built the Grand Canal 1,500 miles long linking north and south China. Everything then changed with the invention of ocean-going ships and guns in the 13th and 14th centuries. (The gun innovation took only 40 years to spread from China to Europe.) Suddenly the most important geographic fact was the differing sizes of the Atlantic and Pacific oceans. Europeans had only 3,000 miles to travel to conquer the Americas; the Chinese (who had capable ships) faced a 6,000 mile barrier. Atlantic trade gave Europe the wealth and science to start the industrial revolution, and with that the West unleashed a global economy, within which players in the East are now flourishing rapidly.
Extending the story to the rest of this century, Morris says that if present trends merely continue, the East will retake leadership by the end of the century. But the accelerating pace of social development may make geography irrelevant. By his index, societies have risen to an index value of 900 during the past fifteen millennia. They are likely to be at a level of 5,000 by century's end, meaning there will be five times as much progress (or catastrophe) in this 100 years as in the past 15,000 years.
Books about the future, Morris noted, nearly always portray the future as much like the present. "That," he said, "won't happen."
Ian Morris is the author of Why the West Rules - For Now.-- by Stewart Brand