As an aside, someone emailed me that Chapter 21 had been translated into English on Scribd, but I don't have a membership. They give a 1-page free teaser (slightly improved by me), which will give you an idea of the subject matter discussed in the book:
Do Adrien Gréa
–
The Church and its Divine Constitution
Chapter XXI
The extraordinary act of the episcopate
Of what it consists
The power of the episcopate in the government of the universal Church exercises itself in an ordinary way through the councils and through the less splendorous assistance which the dispersed bishops, always united in the dependence and under the impulse of their head, give without ceasing for the maintenance of the faith and of discipline.
But this power of the episcopate has also had in history extraordinary manifestations of which it is important to be brought back to the same subordination and to be submitted to the same essential laws of the hierarchy.
We want to speak here primarily of the authority deployed by the apostles, their disciples, and the bishops of the first times, their successors, to announce everywhere the Gospel and establish the Church, and secondarily of the extraordinary actions by which, subsequently, one saw bishops not hesitate to remedy the pressing necessities of the Christian people and to lift up again, by the use of a power quasi apostolic, Churches brought into extreme peril by the infidels and the heretics.
These facts have been abused to pull out of proportion the authority of the bishops and to give them a sort of primitive and independent sovereignty.
It is thus necessary to overthrow this fundament of error. We will do so in simply recalling the doctrine exposed in our second part, principally in chapter 8, where we have treated of the relations of essential dependence that unite the particular Churches to the universal Church, and in bringing back these facts to the laws already known of the hierarchy, laws which, everywhere and always, establish the complete subordination of the bishops to their head.
And first, it is good to recall that the universal Church, preceding in everything the particular Churches, possesses before these and guards always sovereignly the mission of preaching the Gospel everywhere and of saving souls.
It follows from there that the hierarchy of the universal Church, who is not deprived of her immediate authority over souls even by the establishment of particular Churches, remains alone charged with the salvation of men when these are defunct, and deploys her powers to assure them this benefit.
This hierarchy is that of the Pope and the bishops. It is to the Pope that belongs the sovereign and principal action. But the bishops themselves, since they are associated with him as ministers of the universal Church, are called to take part in it. They appear thus vested with a power which is not carried out on their particular flocks and which exercises itself in places where there are not yet founded particular Churches and titular bishops established, and in those where the local hierarchies, having been established, are harmed in their existence or struck with impotence.
[This final bolded sentence gets to the heart of the matter surrounding the legitimacy/illegitimacy of Archbishop Lefebvre's episcopal consecrations, and translating Grea's doctrine surrounding this point is my primary interest in the undertaking -SJ]