Rorate Caeli

Authority and Recognition

For the Holy Spirit was promised to the successors of Peter not so that they might, by his revelation, make known some new doctrine, but that, by his assistance, they might religiously guard and faithfully expound the revelation or deposit of faith transmitted [traditam] by the apostles.
Pastor Æternus
First Vatican Council

After the Second Vatican Council, the impression arose that the pope really could do anything in liturgical matters, especially if he were acting on the mandate of an ecumenical council. Eventually, the idea of the given-ness of the liturgy, the fact that one cannot do with it what one will, faded from the public consciousness of the West. In fact, the First Vatican Council had in no way defined the pope as an absolute monarch. On the contrary, it presented him as the guarantor of obedience to the revealed Word. The pope's authority is bound to the Tradition of faith, and that also applies to the liturgy. It is not 'manufactured' by the authorities. Even the pope can only be a humble servant of its lawful development and abiding integrity and identity.
Joseph Cardinal Ratzinger