The follow-up to Pinker's groundbreaking The Better Angels of Our Nature presents the big picture of human progress: people are living longer, healthier, freer, and happier lives, and while our problems are formidable, the solutions lie in the Enlightenment ideal of using reason and science. Far from being a naïve hope, the Enlightenment, we now know, has worked. But more than ever, it needs a vigorous defense. The Enlightenment project swims against currents of human nature--tribalism, authoritarianism, demonization, magical thinking--which demagogues are all too willing to exploit. Many commentators, committed to political, religious, or romantic ideologies, fight a rearguard action against it. The result is a corrosive fatalism and a willingness to wreck the precious institutions of liberal democracy and global cooperation.

"Can reading a book make you more rational? Can it explain why there seems to be so much irrationality in the world, including, let's be honest, in each of us? These are the goals of Steven Pinker's follow-up to Enlightenment Now (Bill Gates's 'new favorite book of all time'). Humans today are often portrayed as cavemen out of time, poised to react to a lion in the grass with a suite of biases, blind spots, fallacies, and illusions. But this, Pinker a cognitive scientist and rational optimist argues, cannot be the whole picture. Hunter-gatherers--our ancestors and contemporaries--are not nervous rabbits but cerebral problem-solvers. A list of the ways in which we are stupid cannot explain how we're so smart: how we discovered the laws of nature, transformed the planet, and lengthened and enriched our lives. Indeed, if humans were fundamentally irrational, how did they discover the benchmarks for rationality against which humans fall short? The topic could not be more timely. In the 21s