Uniquely heterogeneous and uncoerced consensus on beliefs, following a consensus on theories and cognitive values was established among a large group of historians almost simultaneously in much of what would become Germany during the first half of the nineteenth century and spread from there to the rest of the world. The unusual (Laudan, 1984) simultaneity of the acceptance and spread of consensus on historiographic beliefs, theories, methods, and cognitive values occurred because they were imported wholesale to historiography from other disciplines – biblical criticism, classical philology, and comparative linguistics – where they had already been established earlier. The spread of these theories and cognitive values was gradual geographically across the Rhine and the disciplines, through historiography to evolutionary biology and archeology and backward, when newer disciplines exported back improved methods and theories to the disciplines from which they had imported them earlier. The expanding overlapping theoretical basis of these disciplines allowed them to achieve scientific consensuses on beliefs since the second half of the eighteenth century. In this chapter, I trace the historical development of this overlapping theoretical basis. The next chapter analyzes the results of this study in philosophical terms.

An identical set of cognitive values and theories both defines the community of historians, and must be assumed in the current inquiry into the historical emergence of this community of historians.