Logic seems like a simple thing. And yet, somehow, mistakes in logic happen all the time. But how do these mistakes, these "fallacies," happen? Maybe they are caused by a lack of knowledge. Maybe they are caused by a lack of critical thinking. Maybe they are caused by small monsters that live in people's heads, encouraging them to believe someone's lies, or maybe pick the easy, deceitful way to win a difficult argument. This book is about those monsters.