In theory, an Ecumenical Council can teach either/both infallibly or non-infallibly. And a non-infallible teaching can err, though not gravely. But I’ve never found any error of any type in any Ecumenical Council’s teaching. Perhaps Ecumenical Councils are infallible in all that they teach.
As for Vatican II, in all the many years of study of those documents, I’ve never seen any error at all, no matter how small, in any teaching of that Council. And when has any Council or Pope ever corrected a non-infallible teaching of a past Council?
I suggest that perhaps all Ecumenical Councils are inerrant in all that they teach as a truth of Tradition, Scripture, Magisterium.
So many times, when people claim that Vatican II erred, they simply compare their own understanding to that of the Council and assume that the Council errs whenever the two disagree. Essentially, the critics of Vatican II assume that their own mind is infallible. They don’t say that. But it is an assumption in their every argument against a Pope or a Council.
My faith tells me to accept everything that the Second Vatican Council teaches on faith, morals, and salvation. I don’t put my reason above the Council to continually judge its every teaching. I have faith in the teachings of Christ in that Council. And the result is peace, holiness, faithfulness to God and faithfulness to each and every Pope.
I stand on faith, not on my own fallen reason.
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