What do such disparate events as Occupy Wall Street, Iran's Islamic revolution and Venezuela's socialist revolution have in common? Often, resentment based on past grievances or shortcomings seems to emerge from the depths of individual and collective psyches over the course of such emotionally charged movements. This resentment, and the related philosophical concept of ressentiment, can have a profound impact on the course of history and on the role of leadership within societies. Expanding on the concept of ressentiment, this book addresses the importance of emotions in historical events. The author explores the conditions that foster the development of ressentiment, the role of leaders and followers, and the phases of the phenomenon as it encourages destructive behaviors such as murder and suicide. Often considered an incurable disease with destructive social and political repercussions, it is a core motive for acts of terrorism, revolutions, social upheavals and processes of toxic leadership. The author puts forth a model that helps to describe certain historical processes led by ressentiment, like some revolutions and terrorist acts, and to distinguish them from other movements that are usually treated as similar (e.g., independence revolutions). The book then tackles a seemingly impossible question: Can we find a cure for this powerful and destructive impulse? With care and deliberation, the author demonstrates the power of ethical leadership, recognition and redemption as positive unifying forces during human conflicts. A philosophical endeavor to understand events from the Boston Tea Party to Occupy Wall Street, from the French revolution to Hugo Chavez's revolution in Venezuela, this book will be fascinating reading for scholars and students of the social sciences and humanities and those with a particular interest in leadership.