Marcel Lefebvre, an associate pastor, missionary bishop, papal delegate, and superior general of a missionary congregation, was a man of action. His intellect, without being very speculative, was nevertheless imbued with doctrine. In forming priests, he taught the profound nature of the Catholic priesthood and spread its spirit and virtues.
I say this in the presence of God: I had the very great and undeserved honor of being his theologian. Sworn confidentiality prevents me from speaking about the work that I did under him, but I betray no secret by telling you that Archbishop Lefebvre is a theologian, and by far superior to his own theologian, and God grant that all the [Council] Fathers might be theologians to the same degree as he is! He has a perfectly sure and refined theological habitus, to which his very great devotion to the Holy See adds that connaturality that allows him, even before discursive thinking intervenes, to discern intuitively what is and what is not compatible with the prerogatives of the Rock of the Church.
He in no way resembles those [Council] Fathers who, as one of them had the gall to boast publicly, used to take from the hands of a peritus [expert], in the car that was bringing them to St. Peter’s, the ‘ready-made’ text of their intervention in aula [in the Council Hall]. Not once did I submit to him a memorandum, a note, or an outline, without him reviewing, recasting, rethinking and sometimes rewriting them from start to finish, by his own personal, diligent work. I did not ‘collaborate’ with him; if the word were English I would say that I really ‘sublaborated' with him [i.e., worked under his supervision], in keeping with my status as a private theologian and his honor and dignity as a Father of an Ecumenical Council, a Judge and Doctor of the Faith together with the Roman Pontiff.” (January 3, 1964)