This book sets out to demonstrate how violence over history is on a downward trajectory and that we currently live in the least violent time in history by almost every metric. This is very counter intuitive considering we have gotten so efficient at killing people; indeed, we have invented weapons capable of wiping out the human race, but they have yet to be used. The future is a little more optimistic than it appears at first glance. This book starts by outlining various trends he found of violence that has drastically been reduced. For example, homicide, war, torture, executions, and lynching have all been in decline for some time. In the next section he talks about 5 factors that contribute to these declines. The first factor is “The Leviathan” borrowing the term from Thomas Hobbes who argues that even though governments are somewhat arbitrary they nonetheless decrease violence on the overall. The second factor contributing to peace is the concept of commerce. As they say, “if goods don’t cross borders, soldiers will”. Thirdly he attributes the feminization of culture as a cause for the drop in violence. He draws some very interesting correlations between cultures of honor and violence that I hadn’t thought of before. Honor much like a religious ideal can be inflated to infinite proportions leading to tiny insults being cause for a duel to the death. He then draws parallels between the duels of gentlemen from the past and gang violence in the present, showing how the motivation behind the violence is similar, it is just that one had been romanticized more. The ultimate example of this “honor” oriented violence is the era of chivalry. As women stopped being property to be fought over like oil or gold, many of these types of honor-based violence have decreased. Women also tend to be less aggressive on the whole, for example women are less likely to vote for hawkish foreign policy when compared to men. So as their ability to contribute and influence society has grown so too has their more peaceful ideas. The fourth cause in the decrease of violence is cosmopolitanism. He cites the printing press as having an outsized effect on people’s perceptions of other people. Crediting novels as the medium that allowed people for the first time to see the world from a different perspective. Doing this allowed people to feel the pain of others in ways that were not possible before literacy. The final reason he cites is what he labels “The escalator of reason”. He argues that enlightenment and humanist traditions have been the most successful tool in humanity’s arsenal for decreasing violence. To put it simply, if you believe in logic when you ask someone not to hurt you, by extension you also must apply the same logic to see that they themselves don’t want to be hurt. Thusly expanding our circles of consideration and integration. This book is well written, fairly easy to digest. It is full of interesting anecdotes and statistics that Pinker marshals to back his various claims. I enjoyed it, although I feel as if the book could have been shortened by a fair bit without sacrificing on content. There is some controversy as to his way of counting war violence to come away with the results he did, but no one can argue that violence has been restrained quite a bit since the Middle Ages. Especially when you consider the spine-chilling methods of executions and tortures employed and the complete lack of consideration for the welfare of humans that don’t look like you.