Political Science operates with key terms. Key terms are theoretically informed, and they define the objects of the discipline as well as the basic units of analysis. They are oftentimes used to validate the significance of the discipline and, what is more, key terms are “welterschließend” since they map and construct the political universe as a whole. Varying over time, they are subject to historical change and contestation, reflecting political conflicts and transformations outside academia. Key terms transport scientific and political imagination and orientate scientific and political conduct. The presentation reconstructs and interprets the political imagination of Political Science in West-Germany after the Second World War through a critical analysis of several key terms such as “Politik”, “politisches System”, “Steuerung”, “Deliberation”, and “Governance”.