The chapter introduces the scientific-theoretical aspects of cognitive neuroscience, which ultimately arise from the fact that the human brain is interested in its own cognitive process and uses neuroscientific methods to investigate, understand and possibly even technically reconstruct its own brain function. Based on an overview of the history of science on the respective hypotheses and attempts to explain brain function, it is shown that this is a fundamental epistemological problem. Against the background of the different ideas about brain function over the centuries, it becomes clear that our current knowledge of brain function and also the current findings on the functional neuroanatomy of language should by no means be overestimated in its explanatory power.