It is becoming increasingly difficult to know what's real. We live in a world replete with deception, biases, fake images that seem indecipherable from real ones, and widespread and coordinated efforts to misinform us. Not unrelated to this, belief in conspiracy theories and the paranormal are flourishing. This course will explore the reasons why we so often believe claims that scientists reject and accept contentions that powerful and sinister conspirators are secretly controlling major events. We will investigate who believes, why we believe, and how normal human thinking processes contribute to the holding of questionable beliefs. The course will equip students with tools to evaluate claims and to understand why people believe what they do.