I know that it is a coherent extension and illumination of tradition for the same reason that I know that the documents resulting from the Council of Trent and all ecumenical councils are coherent exstensions and illuminations of tradition. It's that simple. Some might call it simplistic, but I call it a radical faith in the power of the Holy Spirit acting in and through the Church. That being said, I respect the Catholics who disagree with my position as long as they exhibit a genuine piety and love for the Church.
"Since cause and effect cannot be seen with the naked eye, and there remains, therefore, conjecture on the matter of cause, I believe it legitimate for Catholics to be able to debate the nature of the cause(s), which have produced the effects in the Church of the present time--many of which are documented. If all aspects of a council are precluded from any such discussion, on the assumption that all aspects of all councils are somehow sacrosanct and divinely inspired, then we do a disservice to the pursuit of truth and a remedy, in my opinion. There are ambiguities and omissions in, and false translations of, documents of the recent council which have been used and misused by certain elements within the Church, with devastating results. Similarly, things never envisioned or commented upon by the council have been carried out, in the name of the council—the radical changes to the Sacred Liturgy, for instance. This has now gone on for four decades; one wonders if this will continue for centuries. It will, if we label those who raise the question as unfaithful, or those who object as dissenters.
"Some might call it simplistic, but I call it a radical faith in the power of the Holy Spirit acting in and through the Church."
I also believe that the Holy Spirit acts in and through the Church and that He truly does bestow the gift of infallibility on her. However, infallibility is a negative charism in that the Church will be prevented from formally defining doctrine which is false.
It does not mean that long and rambling conciliar documents which do not intend or even claim to make formal doctrinal definitions will be so preserved - especially where these have been deliberately subverted by enemies of the Church who have subsequently declared their intention of planting "time-bombs" within them.