From William of Ockham wiki:

Political theory

William of Ockham is also increasingly being recognized as an important contributor to the development of Western constitutional ideas, especially those of government with limited responsibility.[35] He was one of the first medieval authors to advocate a form of church/state separation,[35] and was important for the early development of the notion of property rights. His political ideas are regarded as "natural" or "secular", holding for a secular absolutism.[35] The views on monarchical accountability espoused in his Dialogus (written between 1332 and 1347)[36] greatly influenced the Conciliar movement.[37] This tract on heresy had the ultimate purpose to establish the possibility of papal heresy and to consider what action should be taken against a pope who had become a heretic.[38]

Ockham argued for complete separation of spiritual rule and earthly rule.[39] He thought that the pope and churchmen have no right or grounds at all for secular rule like having property, citing 2 Timothy 2:4. That belongs solely to earthly rulers, who may also accuse the pope of crimes, if need be.[40]

After the Fall he believed God had given humanity, including non-Christians, two powers: private ownership and the right to set their rulers, who should serve the interest of the people, not some special interests. Thus he preceded Thomas Hobbes in formulating social contract theory along with earlier scholars.[40]

William of Ockham said that the Franciscans avoided both private and common ownership by using commodities, including food and clothes, without any rights, with mere usus facti, the ownership still belonging to the donor of the item or to the pope. Their opponents such as Pope John XXII wrote that use without any ownership cannot be justified: "It is impossible that an external deed could be just if the person has no right to do it."[40]

Thus the disputes on the heresy of Franciscans led Ockham and others to formulate some fundamentals of economic theory and the theory of ownership.[40]

According to John Kilcullen, "Ockham's Utilitarian theory of property, his defence of civil and (within limits) religious liberty, and his emphasis on the inevitability of exceptions to rules and the need to adapt institutions to changing circumstances, anticipate J.S. Mill" (via Aristotle).[41]