The Max Planck Society (MPG) has presented itself since its reestablishment in 1948 as a refuge for basic research in the Federal German Republic. This programmatic claim developed under the political conditions of the middle 1940s, during which the end of the Second World War overlapped with the beginning of the Cold War and the western part of the subjugated “Third Reich” very quickly was drawn in as the inevitable junior partner of the western alliance. Within an American-dominated discourse, what had up until then been a hybrid concept changed into a dichotomous one: basic research was described as being clearly distinguishable from applied research, that is, as not immediately relevant for politics, economics, or the military. It was moreover elevated to a symbol of freedom, created by the western democracies to use against the totalitarian Stalinist opponent. With this semantic charge, the concept of basic research forged during the Cold War did three things for the MPG: as far as dealing with the past was concerned, it helped obscure the hybrid character of research, which the Kaiser Wilhelm Society had demonstrated as part of the NS-regime, especially in armaments research. With regard to contemporary politics, during the immediate postwar period it helped legitimate the organizational integrity of the MPG, its institutional independence, and the scientific autonomy of its members. For the future, the commitment to basic research remained a constantly renewing, yet diffuse mission. Debates about closing, reforming, or reestablishing Max Planck institutes show that the research plans were supposed to satisfy the claims about “basic research,” but also that this yardstick could never be calibrated in a binding way. Basic research served as a vague yet undisputed parameter for strategic scientific decisions within the MPG and its positioning in the scientific system of the Federal Republic.