Includes bibliographical references (pages 493-524) and index.

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.