Earlier this month I put up a post on this blog which asked this question: why would anybody in their right mind, back in the Neolithic, go to the trouble of quarrying large slabs of rock from stupid places like Carn Goedog or Craig Rhosyfelin when they could have picked up all the stones they needed from almost anywhere in the landscape?
This came up in my seminar in the Swansea Geography Department the other day, in the context of a discussion about the collection of stones to be incorporated into cromlechs and other stone settings. We talked quite a bit about cost / benefit ratios and agreed that as far as any of us knew, all of the big capstones used in Welsh cromlechs were probably used exactly where found (many were glacial erratics), and were maybe levered upwards or propped up in some cases, whereas the vertical or supporting stones, which tend to be smaller, might have been brought in from within the neighbourhood, with a search extending outwards from the building site until the costs of the exercise outweighed the benefits. I'm increasingly convinced that the LOCATIONS OF DESIRABLE CAPSTONES is what has determined the location of cromlechs across Wales -- and this of course is what Steve Burrow has said quite forcefully in his book "The Tomb Builders."
So the signs are that the Neolithic tomb builders knew all about costs and benefits, and were far more concerned about economy of effort than they were about aesthetics, or astronomical alignments, or the magical or healing properties of the stones they were using.
The consensus in our discussion was that the Neolithic tribesmen of North Pembrokeshire would have been completely stupid to have actually quarried monoliths at Carn Goedog or Craig Rhosyfelin, given the superabundance of convenient stones already littering the landscape following the events of the Devensian glacial episode. And the signs are that they were not stupid at all, if the arrangements and characteristics of West Wales stone settings is anything to go by.
So who were, or are, the people behaving obsessively or irrationally in this whole business? Sadly, we have to conclude that the ones who appear to have taken leave of their senses are the quarry hunters themselves, who appear to have set themselves upon a course of action where the minimalist returns are out of all proportion to the effort and cash expended, and who appear to have learned nothing at all about cost-benefit considerations from their Neolithic ancestors.