Another telling of history highlights overthrowing tyrants, expelling colonizers, and, by marshaling the strength of numbers, progressively emancipating ourselves from slavery, poverty, and other degradations.

The key to deciding which of these perspectives is predictive of the human future lies in a paradoxical property of power. Once it's understood that a group's competitive success vis à vis other groups depends on limiting abuses of power within the group, King's optimism regarding the curvature of the moral arc of history is vindicated.

Here's the gist of the argument: If a ruler is regard