The relevance of historical knowledge for educational theories has been stressed more and more the last 30 years. However, the relevance of theoretical prerequisites for the historical research was less discussed. Against this background this papers follows the methodological thesis that knowledge stemming for historical research depends to a great extent from the research design and thus from basic theories. This thesis is verified by examining historical sources by three different theoretical assumptions. My sources are all the documents of a private school in 18th century Switzerland (1761-1777). The paper wants to find out the organizational reasons that caused the closure of the school after eleven successful years (1761-1772). The following three assumptions are being tested: Firstly the neo-institutional assumption that schools are always embedded in a historically grown institutional environment that shape the schools, secondly the systems theory assumption whereupon schools are closed systems, and thirdly the assumption that organization live on the charisma of their leaders.The methodological thesis of this paper can be affirmed if those three differing assumptions generate different explanations why the school had to close. The outcome of this would be to ask for more transparency concerning the theoretical assumptions of the historical research in order to make the results of this research revisable. Meyer, J.; Rowan, B. (1977): Institutionalized Organizations: Formal Structure as Myth and Ceremony. American Journal of Sociology, 83 (2),. pp. 340-363. Luhmann, N. (2000): Organisation und Entscheidung. Opladen. Weber, M. (1921): Wirtschaft und Gesellschaft. Tübingen.