The first book on your list is an anthology, "Fairy Tales from Donegal".

I've had a copy of this book near to hand for over 25 years, and it is a must for anyone wanting to understand the mindset of rural Ireland. It consists of tiny tales told by Irish speakers in Donegal about fairies and magical animals like hares and ghost horses, of how fairy houses could be found at certain moments of the year on the hills, or how a lullaby, or a baby, could be stolen. The stories were all told as being true, and as having happened just a year or two back. 'Long ago there was spinning in every house of this parish, and all the old women had the custom of taking the wheel band off at night. If they did not do so they thought the wee folk would be spinning with the wheel until morning. It is always said that it is not right for either man or woman to take the spinning wheel out after nightfall. People know that anyone, man or woman, who does so will be led astray by the fairies.' Reading this book you can see how country life was dominated by rituals which were designed to appease the “little folk”, the spirits of the place, who would do mischief if the wrong things were done. Probably these beliefs go back to the very beginnings of man’s existence in Ireland.

And the story of how these tales were collected is extraordinary in itself.

Sean O hEochaiadh was a fisherman and self-taught folklorist who recorded these stories over decades from Gaelic-speakers in Donegal. He had a huge Ediphone that he would haul up to people's homes, often on foot, and then he would coax them to spin their tales which he recorded on wax cylinders, transcribing them later by hand. His persistence, and his deep love of his County and its inhabitants, have preserved for us what is in effect a core-sample of the history of Irish beliefs and language, and there is little doubt that without him much of it would have been lost.

I'm intrigued by your choice of David Lewis-Williams' "The Mind in the Cave". Isn't this about the origins of cave art?

This book has been my constant companion as I have tried to understand Ireland’s prehistory. Lewis-Williams offers a bold new framework for interpreting Stone Age concepts of the universe. He describes very convincingly how these were heavily influenced and defined by the trance experiences of shamans, which seemed to show that there were many levels of spirits which could be contacted and which had to be appeased or appealed to for the sake of the tribe’s prosperity. Caves played a vital role in this story, as people would go into them to hallucinate, believing that they were passing through the cave walls into other spirit worlds and dimensions, and could then return to describe what they had seen. Such phenomena as the cave paintings in France and Spain resulted from these, and it is fascinating to see that the same things were believed to be happening in Ireland. Ritual and legend was centred around natural caves like Oweynagat, where the ancients believed they had an access point for Other World spirits, and also in artificial structures like Newgrange, which is older than Stonehenge or the Great Pyramid of Giza. By building Newgrange to align with the passage of the sun at the winter solstice, Neolithic farmers kept the sky goddess Boinn trapped, and allowed her to be penetrated by their very male sun god once a year.

So it's more about structures of belief than about the cave paintings themselves?

Yes, and also about how our spiritual rites may be, to some extent, determined by the structure of the brain, hence the persistence and resilience of common threads in rituals across continents and through layers of history.