Hatred is a multifaceted feeling of absolute and deep antipathy. It leads to disadvantage, contempt, discrimination, abuse, and even to genocides and wars. It exists in many forms - self-hatred, misogyny, xenophobia - and for various reasons - envy, fear, insecurity. Although much has been written about hatred, this dark side of human nature, which is often contrasted with love in its strength and unwavering nature, remains difficult to explain. In this volume, psychologist Rolf Haubl and philosopher Volker Caysa venture into the realm of hatred and explore it to its very last corner. It becomes clear that anyone advocating for peaceful coexistence among individuals, groups, and nations must understand the necessity of hatred and learn to comprehend the physical and psychological suffering it entails.