known as a wicker man. A differing account came from the 10th-century Commenta Bernensia, which stated that sacrifices to the deities Teutates, Esus and Taranis were by drowning, hanging and burning, respectively (see threefold death). Diodorus Siculus asserts that a sacrifice acceptable to the Celtic gods had to be attended by a druid, for they were the intermediaries between the people and the divinities. He remarked upon the importance of prophets in druidic ritual: Archaeological evidence from western Europe has been widely used to support the view that Iron Age Celts practiced human sacrifice. Mass graves found in a ritual context dating from this period have been unearthed in Gaul, at both Gournay-sur-Aronde and Ribemont-sur-Ancre in the region of the Belgae chiefdom. The excavator of these sites, Jean-Louis Brunaux, interpreted them as areas of human sacrifice in devotion to a war god, although this view was criticized by another archaeologist, Martin Brown, who believed that the corpses might be those of honoured warriors buried in the sanctuary rather than sacrifices. Some historians have questioned whether the Greco-Roman writers were accurate in their claims. J. Rives remarked that it was "ambiguous" whether druids ever performed such sacrifices, for the Romans and Greeks were known to project what they saw as barbarian traits onto foreign peoples including not only druids but Jews and Christians as well, thereby confirming their own "cultural superiority" in their own minds. Nora Chadwick, an expert in medieval Welsh and Irish literature who believed the druids to be great philosophers, has also supported the idea that they had not been involved in human sacrifice, and that such accusations were imperialist Roman propaganda. Philosophy Alexander Cornelius Polyhistor referred to the druids as philosophers and called their doctrine of the immortality of the soul and reincarnation or metempsychosis, "Pythagorean": Caesar made similar observations: Diodorus Siculus, writing in 36 BCE, described how the druids followed "the Pythagorean doctrine", that human souls "are immortal and after a prescribed number of years they commence a new life in a new body". In 1928, folklorist Donald A. Mackenzie speculated that Buddhist missionaries had been sent by the Indian king Ashoka. Caesar noted the druidic doctrine of the original ancestor of the tribe, whom he referred to as Dispater, or Father Hades. Druids in mythology Druids play a prominent role in Irish folklore, generally serving lords and kings as high ranking priest-counselors with the gift