This handbook unites leading scholars from around the world in exploring anarchism as a political ideology, from an examination of its core principles, an analysis of its history, and an assessment of its contribution to the struggles that face humanity today. Grounded in a conceptual and historical approach, each entry charts what is distinctive about the anarchist response to particular intellectual, political, cultural and social phenomena, and considers how these values have changed over time. At its heart is a sustained process of conceptual definition and an extended examination of the core claims of this frequently misunderstood political tradition. It is the definitive scholarly reference work on anarchism as a political ideology, and should be a crucial text for scholars, students, and activists alike.