This article explores how Marsilius's theory of “priestly despotism” underpins his understanding of the civic body's secular authority and autonomy. Marsilius defends this autonomy not only with respect to truly secular matters but also with respect to the citizens' future in the afterlife; consequently, it affects the outlook of the entire commonwealth. In Marsilius's view, though he never doubts the need for the priesthood in the commonwealth, priests represent a fundamental threat to the stability and well-being of the community. Marsilius redefines the position of priesthood to ensure the political stability of the commonwealth by minimizing the danger of internal turmoil. The topic of “priestly despotism” also reveals the internal consistency and logic of Defensor Pacis's first and second discourse by demonstrating how arguments introduced and developed in the first discourse are consistently applied in the second discourse.