Final answer:
The Magisterium derives its authority from the belief in Petrine Succession and historical recognition of the Pope's spiritual jurisdiction.
Step-by-step explanation:
The Magisterium, the teaching authority of the Roman Catholic Church, derives its authority from different sources. One source of its authority is the belief in the Petrine Succession, which asserts that the Pope, as the successor of Saint Peter, holds the keys to heaven and has supreme authority over the Church. This authority is seen as being passed down from the early popes who claimed total authority over other bishops. Another source of authority for the Magisterium is the historical recognition and acceptance of the Pope's spiritual jurisdiction by various bishops and leaders throughout history.