In The Better Angels of Our Nature, psychologist Steven Pinker stakes out a boldly optimistic view of the world, at a time when his readers are no doubt processing all kinds of bad news. Straining at the bigger picture of the trends afoot in human history, Pinker argues that violence is at an all-time low today—and human rights, social equality, and gender egalitarianism are at all-time highs.

With apologies to Shakespeare, we might say that Pinker, who has helped spell out the more arcane findings of his field in best-selling studies such as How the Mind Works (1997) and The Blank