One of the basic principles of science is that good theories extrapolate well. The laws of gravity hold both here and on the moon, and this universality enables us to land a spacecraft on Mars. Darwin drew the theory of evolution from studies of a remote island in the Pacific, but today we use it to explain the emergence of drug-resistant tuberculosis in a city hospital.
The theories of gravity and of evolution are two of our greatest scientific achievements. But in contrast to the universal nature of these laws, our understanding of the human world — the messy realm of newspapers and cafes, traffic jams and gossip, governments and social movements — is remarkably limited.
Take, for example, some of the most basic questions in politics. How do societies resolve conflict? How do new methods for resolving conflict emerge? A newspaper story can give us incredible detail on a particular fight — the war in Syria, say, or the political brinksmanship over “Obamacare.”