"From the bestselling author, media pioneer, and curator of TED, an inspiring book about one of humankind's defining but overlooked impulses, and how we can super-charge its potential to build a hopeful future. Recent years have been tough on optimists. Hopes that the Internet might bring people together have been crushed by the divisiveness of social media. But as head of TED, Chris Anderson has had a ringside view of the world's boldest thinkers...