There's a saying that's attributed to the Dalai Lama: in the practice of tolerance, one's enemy is the best teacher. It's a nice idea, but in reality, when people don't share our values, it's hard for us to tolerate theirs. This week, we talk with sociologist Robb Willer about the common mistakes we make in trying to persuade others of our point of view — and how we can break out of our echo chambers.