Steven Pinker’s The Better Angels of Our Nature may be a more upbeat book than most people can accept. Pinker argues that the rate of violent human deaths of all kinds across the globe has been declining for several thousand years. The 20^th century was a bloody horror, but it is also an example of our selective memory; we forget that the second half of the century was relatively peaceful. Humans, as David Hume observed, tend to “blame the present and admire the past.”

Pinker: “To maintain the credibility of their deterrent threat, knights engaged in bloody tournaments and other demonstrations of macho prowess, gussied up with words like honor, valor, chivalry, glory, and gallantry, which made later generations forget they were bloodthirsty marauders.”

Violent deaths declined in stages. Judging from skeletal remains thousands of years old, the violent death rate among the earliest humans was roughly 15%. That dropped as the first governments began to constrain local murders, feuds, raids, and battles. Then in 17^th and 18^th century Europe, the “humanitarian revolution” reduced the frequency of forms of violence that had been common for centuries: slavery, torture, cruel punishment, even dueling. Since the end of World War II, the world has seen a “long peace” with no wars pitting major nations against each other and no nuclear holocaust. Most recently, the “Rights Revolution” has reduced violence against minorities, women, children, gay people, and animals.

The prominence of death stories in the modern media is misleading. In the 20^th century, only .7% of all deaths occurred in battles, or about 3% if indirect war deaths from famine and disease are included. In Europe and most of America today, the violent death rate is 1% at its highest.

What has caused this steady reduction? In a word, government. Even bad government is better than no government for reducing violence. And expanding education that enables people to glimpse the lives of others seems to have been crucial as well.

The Better Angels of Our Nature has received high praise and some hard criticism. Reviewers have questioned Pinker’s comparison of six-year-long modern wars with the century-long Mongol conquest and have noted the book’s omission of Mao, Stalin, and the impact of colonialism. Many reviewers seem admiring of the book but not convinced; the modern world still seems very dangerous and the bad news never stops.

One reason for the skepticism is demographic. Until 1800, the world numbered fewer than a billion people; it reached 2.5 billion only around 1950 and today soars over 7 billion. This curve skews comparisons of violent death numbers. Ranked by death rate at the time, the deadliest event in world history was the 8^th century An Lushan revolt in Tang China, resulting in 36 million deaths, a sixth of the world’s population of about 250 million. But today, despite the global billions, even a handful of deaths rate as “breaking news.”

About the future, Pinker makes no predictions. By implication he suggests that we need to understand ourselves as well as we can and learn from the past to sustain the decline. At a time when ideologies and technologies seem beyond the control of government and decency alike, The Better Angels is sobering and steadying.