In this next-to-last chapter Pinker gives us reason to hope, arguing convincingly that it is reason itself that has finally shown us humans a way out of the violence that plagued us for so much of our history. To really do this chapter justice, I’d have to quote nearly the whole thing. Read it, particularly the section on Reason (page 642 to 670 in my edition) even if you don’t read the rest of the book.

To completely not do justice to the subtlety and depth of the argument, I can sum it up by saying that self-control and reason grew up together, and that these two forces have utterly changed the way we human beings see one another. It is so much a change for the better, such a clear example of moral progress, that our own humility about it becomes nearly shameful.

When we realized that we could improve our lives by delaying immediate gratification, we built “muscles” of both self-control and logic. Once we were on this logical conveyor belt, there was no getting off. If I learn to put greater value in my future self, I also learn to value others who are not me.

What got the whole thing started? An excellent argument can be made that it was the birth of science that got the ball rolling. What caused the birth of science? It was part and parcel with the European Renaissance, which itself sprang from the realization that the Church, the source of ruinous crusades, torture of heretics, witch burning, and vicious wars, might actually be wrong about a few things.

Galileo and some doubting Cardinals

Once science showed the power of reason, lots of other minds caught on, and the Enlightenment began to show the world a new way. And what a way it has become.

The growth of logic and reason that began in earnest with The Enlightenment has had a startling effect on us that is today known as the Flynn Effect. We are getting smarter. The extra smarts are not pure brain power, like adding memory or processing speed to a computer. Instead, the improvement is in our ability to reason. IQ scores, which are always renormalized to 100, have been adjusted down over the years to prevent IQ inflation. Without this adjustment, the average teenager today would have had an IQ of 130 compared to her 1910 counterparts, making her smarter than 98 percent of the people alive at the time.

On the face of it (like many of the claims in this book) the Flynn Effect seems ludicrous. If people were really that smart today, we’d be living in some sort of golden age, wouldn’t we? Well, I ask you to look around. Not just at the technological and scientific achievements of our society, though these are immense and growing every day. Instead, look at where we stand morally, compared to an amazingly recent past. Now I can’t resist quoting Pinker:

“historians who take the long view have also marveled at the moral advances of the past six decades. As we saw, the Long Peace has had the world’s most distinguished military historians shaking their heads in disbelief. The Rights Revolutions too have given us ideals that educated people today take for granted but that are virtually unprecedented in human history, such as that people of all races and creeds have equal rights, that women should be free from all forms of coercion, that children should never, ever be spanked, that students should be protected from bullying, and that there’s nothing wrong with being gay.”

One final thing to say about the Flynn Effect. It is fast – much too fast to be genetic. My children will have higher IQ scores than I or my wife have. Why? Because in their world they will use their reason muscles more than I did. The same will be true of their children. And so on. We are essentially the same people who once burned witches and cut off our neighbor’s noses. Our genes aren’t changing quickly enough to make the difference. Instead, it is our ways of thinking, our social norms, our educational practices – what David Deutsch would call our memes – that are evolving. This is both frightening – for we could certainly slip back into our destructive patterns – but also uplifting. We chose to escape from our collective terror, and we can choose to go further still.

Certainly things are far from perfect. We can all look around and see cruelty, waste, stupidity, immoral attitudes toward others, and of course violence. But the point is we can see it. We can see that it’s wrong for girls to be sold on the black market as sex slaves. We can see that it’s wrong for gay people to be denied equal rights. We can see that everyone deserves an education, fair trials, protection from thugs and dictators. It was only an eyeblink ago that people didn’t see these things – or, at any rate, not enough people saw them. Less than 200 years ago, slavery was open and accepted everywhere. Less than 100 years ago, women in the US couldn’t vote or hold office. Less than 50 years ago, homosexuals were not just reviled, they were thrown in prison! Today, we all (or almost all, I’m not entirely sure about Rick Santorum) see that these things are wrong.

I also can see that there are things we – I – do that undoubtedly will be seen as evil by our even more rational, and even less violent,¬†descendants. Our treatment of animals, particularly as food, is an obvious example. A less obvious one is our willy-nilly approach to combining our genes to make new people – “What do you mean you never tested your genetic compatibilities? Are you crazy?” But such thoughts only make me more convinced than ever that we are moving in the right direction, we are making the world better, one tiny step at a time. We are living in a golden age – and it’s getting more golden all the time.

One chapter to go!