Cæsar writes: "The Druids in particular wish to impress this on them that souls do not perish, but pass from one to another (_ab aliis ... ad alios_) after death, and by this chiefly they think to incite men to valour, the fear of death being overlooked." Later he adds, that at funerals all things which had been dear to the dead man, even living creatures, were thrown on the funeral pyre, and shortly before his time slaves and beloved clients were also consumed.[1155] Diodorus says: "Among them the doctrine of Pythagoras prevailed that the souls of men were immortal, and after completing their term of existence they live again, the soul passing into another body. Hence at the burial of the dead some threw letters addressed to dead relatives on the funeral pile, believing that the dead would read them in the next world."[1156] Valerius Maximus writes: "They would fain make us believe that the souls of men are immortal. I would be tempted to call these breeches-wearing folk fools, if their doctrine were not the same as that of the mantle-clad Pythagoras." He also speaks of money lent which would be repaid in the next world, because men's souls are immortal.[1157] These passages are generally taken to mean that the Celts believed simply in transmigration of the Pythagorean type. Possibly all these writers cite one common original, but Cæsar makes no reference to Pythagoras. A comparison with the Pythagorean doctrine shows that the Celtic belief differed materially from it. According to the former, men's souls entered new bodies, even those of animals, in this world, and as an expiation. There is nothing of this in the Celtic doctrine. The new body is not a prison-house of the soul in which it must expiate its former sins, and the soul receives it not in this world but in another. The real point of connection was the insistence of both upon immortality, the Druids teaching that it was bodily immortality. Their doctrine no more taught transmigration than does the Christian doctrine of the resurrection. Roman writers, aware that Pythagoras taught immortality _via_ a series of transmigrations, and that the Druids taught a doctrine of bodily immortality, may have thought that the receiving of a new body meant transmigration. Themselves sceptical of a future life or believing in a traditional gloomy Hades, they were bound to be struck with the vigour of the Celtic doctrine and its effects upon conduct. The only thing like it of which they knew was the Pythagorean doctrine. Looked at in this light, Cæsar's words need not convey the idea of transmigration, and it is possible that he mistranslated some Greek original. Had these writers meant that the Druids taught transmigration, they could hardly have added the passages regarding debts being paid in the other world, or letters conveyed there by the dead, or human sacrifices to benefit the dead there. These also preclude the idea of a mere immortality of the soul.