Have you ever wondered how we know the things we know? Or how we have come to understand who we are ourselves and what the limitations of this understanding are? Or how we come to perceive what should be objective facts so subjectively? To some extent, we all realize that our world, as each one of us perceives and reacts to it, is a making of our own. That of course is what constitutes much of the richness of human life, that we can share how we see the world and learn how others see it. But we also often disagree not just on how we perceive things but on what the facts are. This book is for readers interested in what biology, philosophy, and psychology can tell us about the human self, how we as persons learn about the world as we build our own consensus realities. It also investigates some of the consequences which follow from consensus realities taken to the extreme. Nobody today can give an answer to the question as to where the depth of depravity comes from which humans have shown themselves capable of throughout history. However, we do understand to a good extent how reshaping consensus realities enables individuals and societies to cope with the monstrosities for which they bear responsible for which they do not want to be held accountable. This topic should be of interest to most readers taking an interest in the study of human nature.