Pinker identifies six trends in the reduction of violence. Each has the potential to raise the ire of one or another group. Too bad.

1) The Pacification Process

The myth of the noble savage is deeply ingrained and difficult to escape. We’ve all seen and heard about Native Americans, Australian Aboriginals, and so on living in harmony with nature and one another until Western Man arrives to bust it all up. Pinker shows that people living in non-state societies are far more likely to die of violence than those living in societies with strong, centralized governments (the Leviathan of Thomas Hobbes). The conclusion won’t be the only one that runs afoul of politically correct ideas.

2) The Civilizing Process

This conclusion is less politically incorrect and more just plain unbelievable. Could it really be that cities in virtually every period in history were more dangerous than today? With school shootings and murder-suicide in the headlines nearly every day, people just don’t believe the numbers. But they’re all there – homicide rates have been falling for a thousand years, and the overall trend is still down. This is complex chapter with fascinating discussions of the United States and the culture of honor that still may dominate in certain places (they don’t call them “red states” for nothin’), keeping the homicide rate high. There’s also a challenging discussion of the 1960s and the temporary peak in homicide that arose from that era of rebellion, showing again that Pinker can honk off the left and the right equally. But the overall message is both clear and startling. Horrible crimes are news precisely because they are rare.

3) The Humanitarian Revolution

This chapter covers some of the most revolting events in history – human sacrifice, the burning of witches, the torture of heretics, the slave trade. Here Pinker very much mirrors David Deutsch’s thoughts. It was to a great extent the Age of Reason and the Enlightenment that slew these horrible human traditions. Religious people will object that it was the pacifying effects of religion that led to, for instance, the abolition of slavery. A difficult argument to make when for so many years it was religion that was used to justify slavery, witch burning, and so on. Pinker also shows that the counter-enlightenment movements of the 20th century such as nazism, fascism, and communism led to the atrocities of that century, not (as so often is claimed) the enlightenment itself. If you read nothing else in the book, read this chapter. I think it will convince you, as it convinced me, that we must never again allow those who deny reason to wield power over the rest of us.

4) The Long Peace

Another chapter, another seemingly crazy claim. Could the 20th century, with its two world wars, really have been less violent than previous centuries? For two reasons, yes. First, those two terrible wars killed large numbers of people, but the world held more people in this century than at previous times. When couched as a question of percentages, we see that previous atrocities matched or even surpassed the 20th century for body count. Second, after the end of World War II the world entered a period of unprecedented peace. Yes, there were wars, but they were minor compared to the bloodletting of the past. Remember that Pinker’s argument is never that violence has vanished, only that it has declined. Warfare is no exception. A word of warning – don’t be lured in to the easy explanations, such as the advent of nuclear weapons, to explain the long peace. Pinker shows why this and similar arguments don’t work. We really do seem to have entered a new era in which much of the world sees war as a failure.

5) The New Peace

OK, you might be thinking by this time. Organized warfare is down. But surely genocide, terrorism, and even climatic catastrophes have in a sense taken their place. The numbers argue otherwise. Believe it or not (and so many won’t), genocide and even terrorism are actually down over the past two decades. The chapter is again deep and rich, with a challenging discussion of Islam as a force in the world today, again guaranteed to raise many hackles. Pinker is guardedly optimistic here, recognizing the many violent influences still at play in the world today, but also seeing that there is reason for hope.

6) The Rights Revolutions

Hope is the best word to describe the next chapter. The explosion of rights in our recent history is one of the most uplifting stories told in the book. Consider that in 1948 Strom Thurmond ran for president on an avowedly segregationist platform. In 2002, only 54 years later (less than a single lifetime), Trent Lott praised Thurmond’s campaign, and was forced to resign. Women’s rights, children’s rights, gay rights, and even animal rights are described in turn. As a confirmed meat eater, the animal rights section was particularly tough for me. I almost had to put down my jerky. Almost.

These six chapters (2 through 7 in the book) constitute the bulk of the text, and present deeply challenging and often counter-intuitive ideas. I’ve blown through them here because I want to get to the deeper explanations, where I find Pinker’s reason and optimism powerful, affirming, and persuasive. As I said, this overview is not intended to convince anyone. That’s what the book is for. Read it.