"Histoire religieuse de la Bretagne", Georges Minois, Editions J.P. Gisserot.
"Neither temples, nor idols, nor sacred texts to delete, the wind, the rain, the thunderbolt, the moon, the springs, the
stones, the trees are indestructible. The cult may take place anywhere in the moor and the forest, it expresses the most
natural fears and joys of the mind, the inside and mysterious strengths of the Being.(...). Such a religion is nearly
ineradicable.
The catholic clergy succeeded to recover it only by means of series of tricks and compromises, as the conversion to
christianity of standing stones (menhirs)."