Abstract
The paper explains the meaning of law and its political function in Marsilius of Padua’s philosophy. This thinker is interested, above all, in statehood and he points out that law is the ground of civitas (polis or political community). His emphasis on law means that the main question is what makes law, law. It isn’t the content of justice, but the coercive command of the legislator, who has the authority to give law and to punish its transgression, because a law is a command whose disobedience leads to punishment. Therefore such definition of law runs into the question for the law-giver: it is “the whole corporation of citizens or its weightier part (valentior pars)”, that is to say, the rightful representation of the whole community, but never any other part of community, not even priests or doctors. The definition of law, which involves the unity of community and the sole legislator, is the philosophical ground to refute any political power for the Pope or priests to make laws