How did Dante and Marsilius of Padua argue for limits on church authority in secular affairs?

In the 14th century, both Dante Alighieri and Marsilius of Padua utilized Aristotelian principles to challenge the extent of church authority in secular affairs, though they differed in the degree of their critiques.12

Dante Alighieri
In his treatise De monarchia, Dante argued against the papal claim that the empire derived its political authority from the pope. He proposed that humanity is guided by two distinct ends: the bliss of this life (earthly paradise) and the bliss of eternal life (heavenly paradise). While he acknowledged that mortal happiness is ultimately ordered toward immortal happiness, he sought to establish a theoretical framework that protected the autonomy of the secular ruler in worldly matters.3

Marsilius of Padua
In his work Defensor pacis, Marsilius went further than Dante by arguing that the church should be entirely subject to the state in all worldly affairs. He maintained that the state’s primary responsibility is to preserve law, order, and tranquility, and that the source of all political power resides in the people. He concluded that the church's authority in morals and doctrine should be vested in a general council representing both the clergy and the laity, effectively limiting the power of the church hierarchy.21