Just putting the following quotes on the table for discussion/consideration:
Lumen Gentium
"Each and all these items which are set forth in this dogmatic Constitution have met with the approval of the Council Fathers. And We by the apostolic power given Us by Christ together with the Venerable Fathers in the Holy Spirit, approve, decree and establish it and command that what has thus been decided in the Council be promulgated for the glory of God."
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Pope Paul VI closing speech of the council
"We decided moreover that all that has been established synodally is to be religiously observed by all the faithful, for the glory of God and the dignity of the Church and for the tranquillity and peace of all men. We have approved and established these things, decreeing that the present letters are and remain stable and valid, and are to have legal effectiveness, so that they be disseminated and obtain full and complete effect, and so that they may be fully convalidated by those whom they concern or may concern now and in the future; and so that, as it be judged and described, all efforts contrary to these things by whomever or whatever authority, knowingly or in ignorance be invalid and worthless from now on."
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Pope Paul VI address on 23 April 1966 to the Roman Curia
"Whatever were our opinions about the Council’s various doctrines before its conclusions were promulgated, today our adherence to the decisions of the Council must be wholehearted and without reserve[...]
[...] The council was something very new; not all were prepared to understand and accept it. But now the conciliar doctrines must be seen as belonging to the magisterium of the Church and, indeed be attributed to the breath of the Holy Spirit."