Public discourse is in bad shape these days. We all yell at and cancel each other on social media and college campuses, and politicians—especially those on the Trumpist right—lie so much that the very notion of truth threatens to lose any meaning. But, Jonathan Rauch is optimistic that this can change for the better. Jonathan is a senior fellow at the Brookings Institution and the author of, most recently, "The Constitution of Knowledge: A Defense of Truth." Alan Rozenshtein spoke with Jonathan about his book, his diagnosis of our present condition and his hopes for the future.