If you follow the headlines, the world in the 21st century appears to be sinking into chaos, hatred and irrationality. Yet, as Steven Pinker shows, if you follow the trendlines, you discover that our lives have become longer, healthier, safer and more prosperous - not just in the West, but worldwide. Such progress is no accident: it's the gift of a coherent value system that many of us embrace without even realizing it.