The main thesis of Steven Pinker’s latest book is that violence has declined dramatically over time and that we are now living in the most peaceful time in history, and to suggest reasons for this. The decline has not been uniformly steady but has a saw-tooth pattern of periodic upticks of violence followed by steeper drops leading to an overall decline over time.

This is not a proposition that is obvious since many people despair of the state of the world now with wars between nations, civil wars, genocides, and the brutal suppression of dissent seemingly taking place all over the globe. It is in order to counter this perception that Pinker has to write such a long book (running to nearly 700 pages even without the endnotes and citations), amassing the data and evidence and arguments necessary whenever one is making a counter-intuitive case. So the book is heavy with numbers and graphs that could easily become tedious except that Pinker has a deft writing style that lifts the reader whenever the going gets tough. The book has sparked considerable interest and on his website Pinker has responded to some of the reactions and criticisms.

Pinker looks at all manner of violence from all kinds of conflicts, from wars, homicides, slavery, genocides, rapes, rebellions, and others as a percentage of the population at the time they occurred. In other words, he is using as his measure of violence not the actual number of casualties but the probability that an individual living at that particular time was likely to suffer violence and death at the hands of another.

Of the many charts, graphs, and tables in the book, the centerpiece is undoubtedly the table on page 195 that ranks the twenty one worst conflicts in history in terms of the absolute number of deaths and also in terms of its population-adjusted rank. While World War II had a death toll of 55 million that is the largest ever for a single identifiable conflict, when calculated as a fraction of the global population, it barely makes it into the list of the top ten worst conflicts of all time, being just number 9. The eight that rank above it involve some events that most people likely have never heard of, at least in the west. The An Lushan revolt and civil war that took place in China in the 8th century is the worst. The deaths caused by the Middle East and Atlantic slave trades are at #3 and #8 respectively while the annihilation of Native Americans is #7. World War I with its 15 million dead comes in at #16.

The reason for this distorted perception is that people tend to magnify events that they or their immediate ancestors have personal experience with, and discount others. So for us, relatively recent conflicts such as World War II, Vietnam, Iraq, the Rwandan genocide, the Stalin purges, etc. seem to dominate history when, when looked at in terms of the number of deaths as a ratio of population, some of them don’t even register as significant sources of casualties.

People point to the two World Wars of the twentieth century with their terrible loss of life and ask how it can be that the twentieth century is not the worst century in history for violence. Pinker points out that although World Wars I and II were bad, they both occurred in the first half of the century and that the second half had no major conflicts, so the century average was lowered.

In seeking explanations for the decline in violence, Pinker, echoing Peter Singer in his classic work The Expanding Circle, invokes various revolutions that have led to an expansion in our circle of sympathy, so that we now view more categories of people to be like us instead of as the ‘other’, and now view as deplorable acts done to them that might have been acceptable in the past. The Age of Reason in the 17th century, followed by the Enlightenment towards the end of the 18th, leading to a humanitarian revolution in the 19th, followed by the various rights revolutions of the 20th century (civil, women’s, children’s, gay, animal) all led to a rise in the value attached to life and steps being taken to curb violence towards those formerly marginalized groups. While the improvement has been uneven, the overall trend is clear. These measures, combined with the increased state monopoly on the legitimate use of force, the increase in commerce between nations, greater cosmopolitanism, the rise in the status and role of women, and the increased application of knowledge and rationality to human affairs have been major factors in the reduction in the use of violence to resolve conflicts.

So why is it that so many still persist in thinking that things are really bad now and yearn for the ‘good old days’? The decline in violence can have the perverse effect of making things seem to be bad now when in fact they have objectively got better. For example, we are now rightly outraged about the harsher prison sentences that African Americans get when compared with white people who commit the same crimes. And while this injustice needs to be corrected, we should not overlook the fact that not so long ago African Americans would have experienced summary and often lethal ‘justice’ at the hands of a mob for the most trivial of offenses and few would have spoken out in protest. So we have come a long way even as we have yet some ways to go.

While Pinker’s analysis of the data showing a decline in violence and his arguments as to the reasons are persuasive, the book’s main weakness weakness lies in his political analysis. The Canadian-born writer, who is a professor of psychology at Harvard, tends to view politics through a western prism and accepts much of conventional wisdom about political developments. While he does not spare the US and colonial powers for their historical contribution to violence, when he reaches for graphic recent examples to illustrate his points, he tends to pick on Nazis and Communism and other convetional villains and overlook similar examples that are closer to home. For example, when looking at the role of ideology in making leaders pursue policies that result in the deaths of thousands of people, his examples are of Stalin and Mao. But he could well ask the same question of president Truman and his decision to drop atomic bombs on Hiroshima and Nagasaki or Lyndon Johnson’s decision to carpet bomb Vietnam with conventional and chemical weapons that resulted in massive deaths and destruction and long—term harm to subsequent generations. As another example, when trying to understand what might make a soldier gun down a group of defenseless innocent people, his example is of a Nazi soldier massacring a group of Jews during the Holocaust. He does not mention My Lai, though that would also be apropos and is more recent.

It is easy for those who care about the state of the world and what we are bequeathing to future generations to succumb to a sense of despair and think that violence and cruelty are indelible features of our existence that have always existed and will always exist and may be getting even worse as our capacity to harm others increases with the development of more sophisticated weaponry. What this book argues is that while serious problems and conflicts still exist and we are by no means living in a utopia, such deep pessimism is unwarranted. Things are better now than they have ever been and can be yet better in the future as long as we continue to expand the circle of concern to include more and more people within its ambit.

Pinker is careful not to make predictions for the future since who knows what might happen but argues the future can be bright. This book’s main virtue is that it provides hope that is not based on wishful thinking but on data.

In a TED talk on this topic, delivered in 2007, Pinker outlines the main theses that were later developed in the book.

Although long, this is a book that is definitely worth reading and having on your shelf because of the wealth of data that it gathers together between its covers. It is an encyclopedia of the history of violence and thus, at the very least, will be a useful reference work.