We’ve discussed Apostolic Succession in general, and we’ve seen how it came to exit even outside established churches, while still remaining valid. As with most things in life, however, it’s more complicated than it seems at first. That’s what I want to discuss in this post.
For the churches that claim Apostolic Succession, there are two interrelated but distinct issues regarding valid clerical lineage, the internal and external. The internal issue is whether the men (and for some churches, women) whom the church in question chooses to serve as bishops (and secondarily, priests and deacons) are in fact validly ordained in that church’s lineage. In the vast majority of cases, this is a non-issue. All churches claiming Apostolic succession have some form or other of training and “quality control”* system for would-be clerics. There are lengthy periods of training (usually in a seminary), advanced degree requirements, various types of screening and vetting, and so on. Thus, an existing bishop doesn’t ordain just anyone as bishop, priest, or deacon. Furthermore, a minimum of three bishops is required to ordain another bishop (usually, many more than three are involved) as an extra level of caution in making sure the lineage is valid. That is, even if one or two of the bishops are somehow not in a legitimate line of succession, there are enough others involved that there is almost complete certainty of Apostolic Succession being passed on to the new bishop.
The external issue with Apostolic Succession is which purported Apostolic lineages in other churches a given church recognizes. This is where it gets interesting, and sometimes complex.