Christus Dominus 4 and 5 begin the first chapter of the document which commences an examination of the relationship between bishops and the universal Church. Bishops are first and foremost members of a community, “constituted as members of the episcopal body,” the descendant of the “college of the apostles in teaching and pastoral direction.” Their relationship with the pope is made clear, of course:
Together with its head, the Roman pontiff, and never without this head it exists as the subject of supreme, plenary power over the universal Church. But this power cannot be exercised except with the agreement of the Roman pontiff.
However, it is clear from the outset that bishops are not vicars of the pope. It is certainly clear that bishops are to be seen in a higher regard than an upper pyramid level in a marching army. The upper Catholic hierarchy is clearly a body that shares the responsibilities for teaching and pastoral ministry, and as we shall see in later sections of CD, not necessarily limited to one’s own diocese. Also commentary on the role of a bishop in and the right to participate in an ecumenical council:
This power however, “is exercised in a solemn manner in an ecumenical council.” Therefore, this sacred synod decrees that all bishops who are members of the episcopal college, have the right to be present at an ecumenical council.
Section 4 concludes with a quote from Vatican I:
The exercise of this collegiate power in union with the pope is possible although the bishops are stationed all over the world, provided that the head of the college gives them a call to collegiate action, or, at least, gives the unified action of the dispersed bishops such approval, or such unconstrained acceptance, that it becomes truly collegiate action.
Lumen Gentium 22, 23, and 25 is referenced as CD briefly describes the Synod of Bishops and its purpose:
Bishops chosen from various parts of the world, in ways and manners established or to be established by the Roman pontiff, render more effective assistance to the supreme pastor of the Church in a deliberative body which will be called by the proper name of Synod of Bishops. Since it shall be acting in the name of the entire Catholic episcopate, it will at the same time show that all the bishops in hierarchical communion partake of the solicitude for the universal Church.
October’s meeting in Rome treating the topic of the Eucharist is an exercise of this body.
It must be significant that the first concrete description of the role of the bishop deals with the deliberative nature of the bishops, not the hierarchical set-up. Roman offices–the curia–are not part of this first picture at all.