This volume brings together scholars from intellectual history, social sciences, philosophy and theology to evaluate central questions concerning political violence and aggression. This multidisciplinary collection of essays critically investigates forms and modes of justification of political violence from historical and contemporary perspectives, especially within the context of the development of the idea of Europe and modern European identity. What is meant by political violence and aggression? When and under which conditions is it justified? Who has the right to exercise it and against whom? Answers differ depending on various factors such as pre-established ends, available resources and possibilities of action, historical and socio-economic context, the ideological, political, and religious-theological background of the actors. The volume pays special attention to (a) how the above questions have been addressed and answered political, philosophical and theological thought, and (b) what kind of ideological currents and historical events lay at the background of such considerations.