Marsilius, History, and Legitimacy: Guido Terreni and Sibert of Beek Confronting the Defensor pacis

Research on Marsilius of Padua’s Defensor pacis has noted his seemingly novel methods of argument in dealing with ecclesiology, especially his deft use of historical and contextual arguments to manipulate the significance of texts and doctrinal emblems traditionally used to legitimate papal authority. But Marsilius was not alone in using these techniques. His papalist opponents used similar “historical” methods to defend papal legitimacy and the existing church order. And they were not simply adapting Marsilius’s technique, for it is well established that these opponents never saw the text of the Defensor, but worked instead from a brief list of the Paduan’s alleged errors collated by a curial panel. This paper will seek to explain how Marsilius and his opponents chose the same novel mode of argument to address the same set of ecclesiological questions. Its focus will be a comparison of the approaches of Marsilius and two prominent papalist opponents, the curial theologians Guido Terreni and Sibert of Beek. I have examined their works previously, but have not considered this question. The works of Guido and Sibert indicate that the roots of the “historical” method lie in earlier disputes, and that Marsilius, Sibert, and Guido drew from the same sources when they framed their ecclesiological arguments.