ABSTRACT
This chapter argues that in his Defensor pacis, completed in 1324 CE, Marsilius of Padua develops a philosophical method for his political theory based on his reading of Aristotle’s Politics in light of the theory of demonstration from Posterior Analytics. This means that, for a stringent political theory, Marsilius is only willing to accept those tenets that are per se evident—for example, that every society aims for peace and tranquility—and that lead to irrefutable demonstrations regarding the constitution of polities. Since whatever belongs to revelation cannot be demonstrated, Marsilius concludes that the spiritual realm must be excluded from such a theory. He arrives at an idea resembling that of Averroes (Ibn Rushd), but without having read some of the relevant texts by Averroes, such as the Decisive Treatise. Instead, the Averroist milieu in Paris may have been a catalyst for his doctrine.
