Besides (relatively) minor details like the calculation of Easter, how different was Celtic Christianity to Roman Christianity?
I am not familiar with this strain at all. Did they butt heads with Rome over doctrinal issues/theology like the eastern Church often did? Or is it pretty much Roman Catholic plus trippy art?
Celtic Christianity always differentiated itself from Mediterranean Christianity by its less urban-centric character. Celtic/Northern Christian poetry, architecture and art from what I understand shows a greater love for raw, nature from what I've been told.
In practice it was quite different, don't know about theologically. Very monastic, fairly ok with paganism. Monks often married, had weird tonsures and did other shit that rome didn't approve of.
>Wasn't it more of taking folk traditions and christianizing them?
yeah, that too but pagans survived in Ireland for a long time. Druids existed in a secularised form for ages too. There were also plenty of traditions that they just didn't bother christianising at all and left us at it.
It's more that there was never really a conflict in the celtic world. What we have as carryovers from druidic tradition is simply superstition.
That is, it's divorced from ethical, theological or cosmological significance.
The belief in things like fae was never thought to be in conflict with Christianity, because that was just how the world was understood to work. Sometimes babies broke into your house to replace your baby with an identical baby. That happens.
The monasticism is definitely the strongest issue, and Whitby didn't solve it. Until the arrival of the Vikings, there was no urban centers in Ireland, so the concept of a 'diocese' didn't really apply.
This lead to a very strange situation where Bishops were basically powerless in the Irish Church. The Archbishop was still basically bishop of nothing. It was the Abbots that held power, because they were connected to the Irish political tradition of leading men, not owning land. Additionally, they were able to have strong ties/outright alliances with Septs, which couldn't offer the same to bishops.
The pattern of abbots holding more influence over the countryside than the bishops was rampant across all of continental Europeparticularly after the decline of the Carolingian Empire, until Church reformations in around 11th and 12th centuries and the pseudo-isidorian decretals.
>Additionally, they were able to have strong ties/outright alliances with Septs, which couldn't offer the same to bishops.
You're right in saying the Abbots had more power but I wouldn't say Bishops were powerless. Thry had the same legal status as kings in a lot of cases.
In fact I'd say the integration with Brehon law is a fairly significant difference, although this applies only to Ireland and Scotland
Additionally there was never a formal practice of 'adopting' celtic christianity vs Roman Christianity.
Both insisted they were practicing the same faith, and certain practices were under contentious. It would be like talking about 'Mexican Catholicism' today. It doesn't represent something that can be 'adopted'.