This text is a summary of my farewell lecture as a university professor, which Igave on 5 July 2005 as the holder of the professorship for Political Sciences andContemporary History in Mannheim, and which I later elaborated.The analysis of unique historic events, as well as permanent structures andprocess patterns, requires the use of a range of different methods used in thehistorical and social sciences, which take into account the uniqueness of eventsand the regulatory character of structures. The history of society and historicalsocial science are two not entirely compatible research approaches, whichattempt to link the analysis of events and structures in their own differentways. Their common feature can be described as being a socio-historicalresearch approach.In the age of the sovereignty of the people, strong tendencies can be observedtowards a lasting world peace, as well as towards legal and illegal acts of massannihilation, particularly in the form of war and of mass murder. A usefulconcept of peace cannot aim to achieve structural conflict resolution and conflicttermination, but merely a dynamic of regulated conflict, which involves cooperationand which entails a low degree of violence.In European policy, the geographical and socio-political dimensions of theconcept of Europe are conjoined in different ways. Historically, a shift in theimage of a north-south Europe towards a west-central-east Europe and thentowards an east-west Europe can be observed.