I don't recall the comment about Ireland not being Celtic in the
7th century, it certainly was. But there is a question as to whether the
"Celtic Church" is a historically meaningful concept.
The issue seems to have risen out of modern religio-political
issues as much as out of anything else. Some nineteenth century
scholars would have liked to see the "Celtic Church" as
representing something closer to "primitive Christianity", which then
succumbed to Rome in the 7th. century at the synods of Mag Lene
(Ireland, 630 AD) and Whitby (England, 664 AD). Others saw something
positive as Rome brought a "primitive missionary territory" under its
rightful jurisdiction. Both misread the events.
The question raised at both of these synods was a technical one of
the proper method for calculating the date of Easter, which since the
Council of Nicea (4th. c.) was (I oversimplify) the first Sunday after
the first Full Moon after the Vernal Equinox. It's a nifty
calendric/astronomical problem. To make a long story short, at both Mag
Lene and Whitby there was general (but not universal) agreement to follow
Roman practice on this date.
Now what does all this have to do with an independent "Celtic
Church". Many Nineteenth Century historians contrasted this
congregational or national independence with the hierarchical Roman
Catholic Church to assert that the "Celtic Church" rendered no allegiance
to Rome. But that misreads; in the seventh century Rome was not the
executive center of Christendom; it was more like the final appeals
court to insure some uniformity of practice among fairly independent
national churches. In this context, it is significant that both the
group that favored the Roman computation, and those who favored an older
(ironically an older Roman computation) agreed that determining the
practice of Rome was an important factor.
The "Celtic Church", like all Seventh Century Christian churches,
was self-governing but considered Rome as having special authority on
matters of practice and teaching. From this framework, making out the
"Celtic Church" as something special projects modern Catholic vs.
Protestant confessional debates back onto the Seventh Century.
-- Steve McCluskey