This book addresses the question of what sense there might be in giving up securities and consciously and actively placing oneself in threatening life situations. It seeks to uncover the reasons that drive vital individuals—children, adolescents, adults, extreme athletes, entrepreneurs, war correspondents, revolutionaries, missionaries, martyrs, researchers, explorers, and boundary crossers—to follow a value system, a life dream, or a calling that is meaningful to them, even at the cost of crossing dangerous boundaries. What motivates these individuals to set aside the common self-protection rule "Safety first" and to risk themselves for higher life values? After an empirical analysis of eight explanatory models, ranging from pathological to therapeutic to hedonistic approaches, the author arrives at a perspective on the problem area.