What is a Bishop? In the early centuries ... not that I am suggesting the immutability of patterns ... but let's see how this goes ... the bishop was the Man of his Church; chosen within the local Christian Gathering (ekklesia); consecrated for them by bishops representing the Catholica but destined to remain their Apostolic Man until he died (Translation=Adultery)*. He was the Pastor of a Congregation; and when church buildings became common, he had his cathedra, his chair of teaching and ruling, situated in the church building of his congregation, in the midst of the people he pastored Sunday by Sunday and day by day. Some of us have experience of how something like this still works out in some Orthodox communities ... I did in South London ... and a very lovely sight it is too, as the the hairdressers and cafe owners and hospital attendants and wide-boys drift in to seek his guidance or, most commonly, simply to gossip with the man whose hand they kissed as he made them a cup of coffee.
We are, of course, unwise to try to impose too rigid an interpretation on any institution. In the early centuries, there were chorepiskopoi who ran around the countryside bishoping; we know very little about how their episkope operated - there is some evidence that at least some them really did have sees, however small the village - but the story of this institution makes clear that they were viewed with unease, restricted, and finally eliminated ... as we Anglicans might say, the 'period of reception' led to their rejection by the Church. I would see them as a tentative first attempt to deal with the new problems which arose as the Church moved into the countryside. More recent centuries have known the custom of bishops with merely titular sees, both in the East and in the West; I rather agree with what John Zizioulas wrote about this practice ... catty bit coming up now ... before he became Metropolitan of Pergamon. I venture, however, to suggest that in such side-roads we do not discern the essence of Episcopacy.
In much of the first millennium, a Bishop was the Man of his Church in the sense that the People might very well have known him since his childhood; had, perhaps, seen him ordained in their midst as diakonos while a young man; had watched him mature over the years; become Archidiakonos; serve for decades as the Right Hand Man of the Old Bishop both at the altar and in Church affairs; until, upon the old gentleman's demise, he seemed the obvious successor. Such a system enhanced the stability of the paradosis of a Church; diminished the risk of Clever People with New Ideas getting their shifty hands upon the tiller of God's Church. If a bishop taught a different doctrine ex cathedra from what he taught last week, or from what his predecessor had taught, it would be noticed.
In the Church of England, diocesans used to be appointed by the Crown, which was an outrageous system but did at least from time to time provide a bishop of outstanding ability who might not have been successful in a more 'democratic' system. This system was reformed so that a Vacancy in See Committee now submits names for formal approval. On the face of it, this system, with representation of the local Church, the wider Church, and the local community, has a lot to be said for it. In fact, as very different commentators with very different standpoints have pointed out, it leads to a self-perpetuating oligarchy of mediocrities. Because: those committees almost always play for safety by prefering a man who has served as a suffragan. And all suffragans are appointed by the diocesans. And diocesans have a deeply rooted fear of appointing a subordinate who will outshine them. Hence the appallingly low quality of the present Anglican episcopate.
But, mediocrities or not, the individuals thrown up by this system are not - like the bishops of old - Men of their Own Church.
*I am sure readers will recall the immortal exchange between Bertie Stanhope and Bishop Proudie ... I quote from memory ...
Bishop Translations happen less frequently nowadays than previously.
Bertie They've cut them all down to much the same, haven't they?
i.e. the Ecclesiastical Commission had made the revenues of most sees the same by amalgamating and then dividing equally the ancient endowments, inequalities in which had hitherto fuelled the incessant quest of Whig episcopal oligarchs to get themselves translated to wealthier sees.