The origins of Haiti’s inability to rally when the earthquake struck can be traced back centuries (Image: Sipa Press/Rex Features)

SOMETIME around AD 1600, Galileo Galilei is supposed to have climbed to the top of the leaning tower of Pisa and dropped two cannonballs of different sizes and weights over the edge. The point was to test Aristotle’s hypothesis that the speed at which objects fall would be proportional to their weight. If Aristotle was correct, a cannonball 10 times as heavy as another would fall 10 times as fast.

Galileo, in fact, believed that in the absence of air …