Book excerpt: What would you have to believe in order to dress up as a shaman, paint your face, and storm the U.S. Capitol? What could possibly lead somebody to claim that it upholds white supremacy to encourage hard work, self-reliance, rational thinking, punctuality, and politeness? Such behaviors would have been unimaginable only a few years ago. And yet here we are, witnessing millions of people across the political spectrum displaying these clear indications of an epistemically poisoned mind. Both red America and blue America are retreating into their own information bubbles, seceding from a common reality. Both consume far too much misinformation and disinformation, developing worldviews that can sometimes be unintelligible to others. This book explores these disturbing developments and what they mean for our society and implores us all to recover a shared sense of what is true.