The Better Angels of Our Nature (the phrase comes from Abraham Lincoln) is a huge book, 696 pages of text plus 74 pages of notes and references. But “it has to be,” Pinker writes. First he has to convince his readers violence has gone down—in the face of all their incredulity—then he needs to explain how it happened. Pinker’s magic is done with numbers, starting with the hunter-gatherer societies of 10,000 years ago when life was, as philosopher Thomas Hobbes put it, “nasty, brutish, and short.” Data shows that back then the likelihood of a man dying at the hands of another was as high as 60 percent in some regions, more than 50 times the same calculation for the United States and Europe in the 20th century—and that includes two world wars. “If the death rate in tribal warfare had prevailed during the 20th century,” Pinker says, “there would have been 2 billion deaths from wars and homicide, rather than 100 million.”
Pinker looks for explanations for these advances within the individual. Human nature, he says, consists of a constant pull of good and evil. He identifies five “inner demons”—sadism, revenge, dominance, violence in pursuit of a practical benefit, violence in pursuit of an ideology—that struggle with four “better angels”: self-control, empathy, morality, and reason. Over the years, Pinker says, the forces of civilization have increasingly given the good in us the upper hand. Strong centralized governments, international trade, the empowerment of women (“cultures that empower women … are less likely to breed dangerous subcultures of rootless young men”) all help make us kinder, gentler beings. Also important is what Pinker calls “the escalator of reason,” in which people reframe conflict as a problem to be solved through brain instead of brawn.