Nerd Picnic reviewed The Sacred Isle by Dáithí O hOgain
Dense mix of lore, linguistics, and speculation
3 stars
The bottom line is stated early in the book: almost all we know about the pre-Christian Irish was written down by Christians, and the original cultural context of those surviving (and distorted) details is lost. For a historian there is no way around these facts.
The author here uses a lot of linguistic evidence, looking at cognates between Irish names/places and their possible Celtic or Indo-European roots. When necessary, he discusses beliefs and practices from Gaul (roughly France) or Wales instead, because they are better-sourced and presumably similar because of the shared Celtic origin.
There is plenty more to say, but overall I'm glad I read it. Reasonable and convincing claims are mixed with pretty tenuous inferences. That's probably the best that can be done with this topic.