Here is intended a short analysis of Ockham's political theory focussed on his use of some central concepts: "unlawful violence" (violentia), "lawful force" (potentia), and "lawful rule" (potestas). Ockham is devellopping these concepts within the framework of his general assumptions. Establishing rulers is a license given by god to men after the loss of paradise together with the license to sort out property (dominium) in order to make possible preservation. This final aim is justification, standard and limit for rulership. Rulers ought to be measured by their subjects by this original intention. Therefore resistance against unlawful rule, even in violent terms, is not only possible, but is the obligation, if men want to live in a free constitution