I was wondering to myself this morning about how, before the rise of the modern state, temporal authorities tended to own and pass their realms on to their children, while spiritual authorities tended to be elected by the people within the territory they'd eventually serve. Sure, in most Roman Catholic spaces, the Pope had something to say, but generally, I think he had nowhere near the power he did today, and I suspect the opinion of the local bishops surrounding the new bishop's territory were likely to be the most important validators of the election.
So, from the temporal standpoint, we can view this as a simple free market outcome. Landowners who do well would tend to pass on to their children both the genetic capabilities and the training necessary to administrate the land.
The combination of elections and celibacy on the spiritual side is less clear.
What is, however, interesting, is that our temporal leaders use elections and avoid the appearance of passing their power on to their future generations, so we know over time, we get less and less capable temporal leaders.
One could argue that there have been some unfortunate moves on the spiritual side as well- at least in terms of disenfranchising the people. So, whatever benefit we got from the original template has been attenuated.
Now, the real breakdown here is the destruction of the family. The temporal authorities tended to be an outgrowth of decent ownership, and naturally people tended to pass on their possessions to their children. The church structure is modeled on the family, and has suffered greatly from myopia. The most important father is the one at home, and as the war on the natural authority of fathers progresses, the sanity of the models, whether in the church or among the nations, become ever more ridiculous.
I suspect these two governing structures tended to work pretty well in tandem, especially in cases where folks were free to move around. Modern anarcho-capitalists seem to be enthused about a corporate model of government as a service, and they like the idea of non-territorial governments, but I think this misses the reality of man. Men are territorial, yet we must live together. The concerns of the church are not territorial per se, yet bishops still have territories. I suspect it might be better that they be responsible for a specific number of people, but for it to be feasible, those people still need to be located near each other geographically. As for the temporal realm, who will improve a city, unless he owns it? Look at what is happening now, as cities across the country are going bankrupt. Our elected officials weren't thinking about the sort of city they could pass on to their children, but about how much stuff they could take while they still had access to power.