Human sacrifices were also offered when the foundation of a new building was laid.  Such sacrifices are universal, and are offered to propitiate the Earth spirits or to provide a ghostly guardian for the building.  A Celtic legend attaches such a sacrifice to the founding of the monastery at Iona.  S. Oran agrees to adopt S. Columba’s advice “to go under the clay of this island to hallow it,” and as a reward he goes straight to heaven.[816] The legend is a semi-Christian form of the memory of an old pagan custom, and it is attached to Oran probably because he was the first to be buried in the island.  In another version, nothing is said of the sacrifice.  The two saints are disputing about the other world, and Oran agrees to go for three days into the grave to settle the point at issue.  At the end of that time the grave is opened, and the triumphant Oran announces that heaven and hell are not such as they are alleged to be.  Shocked at his latitudinarian sentiments, Columba ordered earth to be piled over him, lest he cause a scandal to the faith, and Oran was accordingly buried alive.[817] In a Welsh instance, Vortigern’s castle cannot be built, for the stones disappear as soon as they are laid.  Wise men, probably Druids, order the sacrifice of a child born without a father, and the sprinkling of the site with his blood.[818] “Groaning hostages” were placed under a fort in Ireland, and the foundation of the palace of Emain Macha was also laid with a human victim.[819] Many similar legends are connected with buildings all over the Celtic area, and prove the popularity of the pagan custom.  The sacrifice of human victims on the funeral pile will be discussed in a later chapter.

Of all these varieties of human sacrifice, those offered for fertility, probably at Beltane or Midsummer, were the most important.  Their propitiatory nature is of later origin, and their real intention was to strengthen the divinity by whom the processes of growth were directed.  Still earlier, one victim represented the divinity, slain that his life might be revived in vigour.  The earth was sprinkled with his blood and fed with his flesh in order to fertilise it, and possibly the worshippers partook sacramentally of the flesh.  Propitiatory holocausts of human victims had taken the place of the slain representative of a god, but their value in promoting fertility was not forgotten.  The sacramental aspect of the rite is perhaps to be found in Pliny’s words regarding “the slaying of a human being as a most religious act and eating the flesh as a wholesome remedy” among the Britons.[820] This may merely refer to “medicinal cannibalism,” such as still survives in Italy, but the passage rather suggests sacramental cannibalism, the eating of part of a divine victim, such as existed in Mexico and elsewhere.  Other acts of cannibalism are referred to by classical writers.  Diodorus says the Irish ate their enemies, and Pausanias describes the eating the flesh and drinking the blood of children among