Reading Thomas Cahill's How the Irish saved Civilization and he talks about one reason the Irish we're attracted to Christianity was because it gave relief to a people that believed sacrifice had to be continual. Wondering if anyone had a different take
I don't think that book is wholly accepted by Celtic scholars - I believe Lisa Bitel, for instance, reviewed it not very favourably.
Whether or not people were actually sacrificed in Celtic Britain is unclear, but at the very least the placing of human skeletons underneath buildings would mean that memory of such sacrifice persisted and that bodies of dead people were deposited with the same intended purpose. That such a custom existed in Celtic Ireland is apparent from a burial in the centre of an embanked enclosure - either a ritual or a dwelling-site - on the Curragh in Co. Kildare. This was of a woman who, to judge from her strained position, seems to have been buried alive.
Dáithi Ó hÓgáin's The Sacred Isle: Belief and Religion in pre-Christian Ireland, p. 46-7.
I'm not sure that human sacrifice was continual, as Cahill seems to say, but it certainly seems to have happened.
If you're interested in the conversion period, I'd recommend Thomas Charles-Edwards' Early Christian Ireland for a really in-depth look at it.
Thomas Cahill's book "How the Irish saved Civilisation" is not a scholarly book and I would not take anything in it at face value. It was very badly received amongst Irish scholars in Ireland. Cahill treats mythology as history, confuses pre historic with historic and seems wholly ignorant about the archaeology of any period that he writes about.
The record on human sacrifice is sketchy. Some bodies found in bogs show some evidence of wounds which could suggest sacrifice or even simple murder. For instance, one body known as Cashel man, was discovered in 2011 having been in a bog for over 2,000 years. Eamon Kelly, Keeper of Antiquities at the National Museum of Ireland, examined the remains and said:
‘It appears that the body had been placed on the bog surface, probably in a pool, and two wooden stakes marked the place of deposition. These would have crossed above the head of the victim, perhaps used to tie down the body or simply mark its location.’... ‘Wounds noted on the body suggest we are dealing with a victim of human sacrifice.’
How common or widespread a practice this was is unknown.
If you want a scholarly read about the pre- Christian period in Ireland I would recommend you should read:
"Pagan Celtic Ireland" by Barry Raftery. "Pre-Christian Ireland". by Peter Harbison.