Every writer, Nietzsche once commented, has an intellectual idiosyncrasy that, once grasped, can be used as a key to interpret their work. In Chester Barnard’s classic text on management theory, The Functions of the Executive, the use of dichotomy is such a key. Barnard uses dichotomy in all his major conceptual frameworks. Analyses his three central sociological concepts: society, organization purpose, and organization authority. Shows that the purpose behind Barnard’s use of dichotomy is political: he is attempting to legitimate the dominance of formal organization in society. His main means to accomplish this is by defining dichotomies in such a way that they either assume the dominance or demonstrate the superiority of formal organization. The result is that Barnard’s use of dichotomy is misleading and contradictory. He tries to conceal the contradictions by the use of complex and ambiguous discussions. Ultimately, Barnard’s theoretical method is shown to rest on the erroneous dichotomy that assumes organization rationality is autonomous from and superior to culture and society.