The history of anthropology has been written from multiple viewpoints, often from perspectives of gender, nationality, theory, or politics. Before Boas delves deeper into issues concerning anthropology's academic origins to present a groundbreaking study that reveals how ethnography and ethnology originated during the eighteenth rather than the nineteenth century, developing parallel to anthropology, or the "natural history of man." Han F. Vermeulen explores primary and secondary sources from Russia, Germany, Austria, the United States, the Netherlands, Hungary, the Czech Republic, Slovakia, France, and Great Britain in tracing how "ethnography" originated as field research by German-speaking historians and naturalists in Siberia (Russia) during the 1730s and 1740s, was generalized as "ethnology" by scholars in Göttingen (Germany) and Vienna (Austria) during the 1770s and 1780s, and was subsequently adopted by researchers in other countries. Before Boas argues that anthropology and ethnology were separate sciences during the Age of Reason, studying racial and ethnic diversity, respectively. Ethnography and ethnology focused not on "other" cultures but on all peoples of all eras. Following G. W. Leibniz, researchers in these fields categorized peoples primarily according to their languages. Franz Boas professionalized the holistic study of anthropology from the 1880s into the twentieth century.