
Introduction
The Defensor Pacis of Marsilius of Padua is one of the most significant works of political philosophy to emerge from the so-called Latin Middle Ages. It is often regarded as the precursor to both the modern theory of the state, modern democratic consent as well as the forerunner to the Protestant Reformation.
The Defensor Pacis is divided into three discourses (Dictiones) of unequal length. In the First Discourse Marsilius sets out his views on the nature and causes of civil society on the basis solely of arguments based on unassisted human reason (I. 1. 8). Chapters 14-19 are famously devoted to questions of rule and rulership, taking up in turn the question of the efficient cause of rulership; the desirable qualities and characteristics of the ruler; how to choose or elect a ruler; the unity of governmental rule in the state; the correction of rulers; and finally and most importantly the papal plenitude of power. The Second Discourse, by far the longest part of the work, consists of a forceful indictment of the doctrine of the papal plenitude of temporal and coercive power, which Marsilius views as the primary cause of strife and discord in cities and states. Here Marsilius argues mainly on the basis of Scripture and Christian authority. The Third Discourse is a summary of the previous Two Discourses and draws a series of concrete conclusions from them.
The distinction between the procedures in the first Two Discourses is one that Marsilius himself thematizes, for he distinguishes throughout between that which is “demonstrated” by “human demonstration” and that which is revealed by God immediately or mediately and therefore is accepted by faith as distinct from reason.
Marsilius titled the book, Defensor Pacis, not Defensor Fides. Marsilius deliberately lowers his sights, but not without good reasons. Accordingly he defends the peace that is the necessary condition for the actualization of the good life, and not the faith that is said to constitute it. The disease with which the Defensor Pacis deals renders any government impossible, for it destroys the unity of the government and of the legal order, or produces permanent anarchy since it consists in the belief that the Christian is subject in this world to two conflicting governments, one spiritual and one temporal. The disease thus endangers both the good life or the fruits of peace – that for the sake of which the Commonwealth exists – but also mere life, or mere peace, which is the necessary condition for the realization of the true end of the Commonwealth.
Thus Marsilius abstracts from the question of the best regime, but never denies its significance, because any regime is better than no regime, and the Church and ecclesiastical authorities are the authoritative interpreters of virtue or the best life, and it is precisely their authority and modes and orders he is at pains to dissolve. And so his focus is on mere law or mere government rather than the best laws or best government. Mere consent then comes to the fore as the principle of legitimacy rather than wisdom or virtue. Marsilius asserts that the only legitimate sovereign is the people, but that the sovereign is to be distinguished from the government. In this way he subordinates the Christian priests to the Christian laity, elevating the Christian demos at the expense of the Christian aristocracy. He seems both to advance the argument for popular sovereignty and to retract it. He appears to vacillate between populism and absolute monarchy.
The solution lies in the following consideration: he sides with the people over and against the clergy, but he takes the sides of the Roman emperors, ancient or medieval, over and against the Popes. In this way, the work is wholly different from that other appropriation of Aristotle and Christianity, the foremost Christian Aristotlean of the Middle Ages, Thomas Aquinus. It is striking that Marsilius refers to Aquinus only once, and simply to quote a text that Aquinus himself had cited from some other source. After all, Thomas Aquinus had accepted and lent his great authority and reasoning’s to the traditional eecclesiastical polity of the very Roman Church Marsilius was bent on transforming.
Marsilius explicit aim is not to set out a complete political philosophy, but to tackle one very specific evil, which Aristotle, living in a pre-Christian pagan dispensation, could not have foreseen: namely, the encroachments of the papacy in the spiritual and temporal spheres and the fraught consequences of such abuses for the peace and prosperity of society. He presents himself as a strict follower of Aristolte, “the pagan sage,” and “divine philosopher.” He agrees with Aristotle about the purpose of the commonwealth: the commonwealth exists for the sake of the good life, and the good life consists in the activity of becoming a free man, i.e., in the exercise of the virtues of practical as well as speculative soul.
In fact, Marsilius seems only to deviate from Aristotle on one singular point, that of popular sovereignty. And that because Aristotle did not know, could not have known, one very grave disease of civil society, “an evil thing, the common enemy of the human race that must be eradicated.” Marsilius goes so far as to declare that this is the sole political disease with which he will deal, all the others having been properly disposed of by Aristotle. The explanation for this deviation is to be found in the doctrine of the Christian priesthood, to which Marsilius denies vociferously most of the perogatives claimed for it by the traditional ecclesiastical regime of his day. While Marsilius admitted that the priesthood was divinely established as distinct from the Christian laity, he denies that the ecclesiastical hierarchy is divinely established. According to him all priests are equal in all respects as far as divine right is concerned. He also denies that any priest, even if he be bishop or Pope, has by divine right any of the following perogatives: the power to command or coerce; the power to decide whether and how coercion is to be exercised against apostates and heretics, be they subjects or princes; and the power to determine in a legally binding way what is orthodox and what is heretical. In this way the Defensor Pacis is perhaps best seen as a kind of appendix to that part of Aristotle’s Politics that is concerned with the diseases of civil society but was ignorant of the Christian doctrine of the plenitude of priestly power.
Likewise, his rejection of the existence of Thomistic natural law (II. 12) is ultimately traceable to the same opposition to the perogatives of the priesthood. He presupposes that reason knows no other legislator than man and hence that all laws properly so called are human laws. Reason is capable of discerning what is honorable, what is just, and what is of advantage to society; but such insights are not as such laws. Moreover, they are not accessible to all men and hence not admitted by all nations, so they cannot be called natural. Granted, there exists rules that are regarded by all regions as just, or honorable and almost universally enforced, which can metaphorically be called “natural rights.” But they are not strictly speaking.natural because they are not dictated by right reason. The universally admitted rules of right are not rational because there exists a natural necessity to transgress them. For example, if wars are by nature necessary in order to prevent over-population, which Marsilius graphically presents to be the case, then the distinction between just and unjust wars is not so sharp.
Spurred by his anti-clericalism, Marsilius consciously lowered the sights of political philosophy. His trenchant opposition to ecclesiastical authority and natural law, with its concomitant neglect of the highest good for man and focus on a law that is directed towards the well being of the body, or bodily security, would exert a profound influence on both the political theology of the Protestant Reformation and the political philosophy that laid the foundations of the modern state.