How did William of Ockham limit the political power of the pope?

William of Ockham limited the political power of the pope by arguing that papal authority is restricted by the freedom of Christians, which is established by the gospel and natural law.1

He maintained that the church is essentially a community of the faithful rather than an institution governed by an infallible authority, whether that be a pope or a council. Ockham further challenged the papacy by asserting that a pope who promotes heresy forfeits his mandate and status. Based on these views, he defended the legitimacy of siding with the empire against the papacy and supported the right of secular rulers, such as the king of England, to tax church property.1