"The decision as to whether an order has authority or not lies with the persons to whom it is addressed, and does not reside in persons of authority or those who issue these orders," according to industrialist Chester Barnard in "The Functions of the Executive," first published in 1938. This statement flatly repudiated the traditional view of authority. Barnard had extensive first-hand knowledge of authority, president of New Jersey Bell Telephone for eighteen years, chairman of the executive committee of the United Service Organization for six years, and finally president of the Rockefeller Foundation. To understand Barnard's impact on authority-flow theory, this article considers a three-stage analysis: the pre-Barnard period, his contributions, and the post-Barnard period. Authority-flow theory since Barnard has undergone four extensive shifts: from simple to complex approaches to the subject matter, from loose to precise concepts of analysis, from an interest in authority to a focus on power, and from impressionistic and small-group research to survey research. There is little reason to doubt that these four shifts will continue along their present paths.