H. 3.—­The earliest testimony is that of Julius Caesar himself, in his well-known sketch of contemporary Druidism (’De Bello Gallico,’ vi. 14-20).  He tells us that the Druids were the ministers of religion, the sacrificial priesthood of the nation, the authorized expounders of the Divine will.  All education and jurisprudence was in their hands, and their sentences of excommunication were universally enforced.  The Gallic Druids were under the dominion of a Primate, who presided at the annual Chapter of the Order, and was chosen by it; a disputed election occasionally ending in an appeal to arms.  As a rule, however, Druids were supposed not to shed blood, they were free from all obligation to military service, and from all taxation of every kind.  These privileges enabled them to recruit their ranks—­for they were not an hereditary caste—­from the pick of the national youth, in spite of the severe discipline of the Druidical novitiate.  So great was the mass of sacred literature required to be committed to memory that a training of twenty years was sometimes needed.  All had to be learnt orally, for the matter was too sacred to be written down, though the Druids were well acquainted with writing, and used the Greek alphabet,[53] if not the Greek language,[54] for secular purposes.  Caesar’s own view is that this refusal to allow the inditing of their sacred books was due to two causes:  first, the fear lest the secrets of the Order should thus leak out, and, secondly, the dread lest reading should weaken memory, “as, in fact, it generally does.”  Even so, amongst the Brahmans there are, to this day, many who can not only repeat from end to end the gigantic mass of Vedic literature, but who know by heart also with absolute accuracy the huge and complicated works of the Sanscrit grammarians.

H. 4.—­Caesar further tells us that the Druids taught the doctrine of transmigration of souls, and that their course of education included astronomy, geography, physics, and theology.  The attributes of their chief God corresponded, in his view, with those of the Roman Mercury.  Of the minor divinities, one, like Apollo, was the patron of healing; a second, like Minerva, presided over craft-work; a third, like Jupiter, was King of Heaven, and a fourth, like Mars, was the War-god.[55] Their calendar was constructed on the principle that each night belongs to the day before it (not to that after it, as was the theory amongst the Mediterranean nations), and they reckoned all periods of time by nights, not days, as we still do in the word “fortnight.”  For this practice they gave the mystical reason that the Celtic races were the Children of Darkness.  At periods of national or private distress, human sacrifices were in vogue amongst them, sometimes on a vast scale.  “They have images [simulacra] of huge size, whose limbs when enclosed [contexta] with wattles, they fill with living men.  The wattles are fired and the men perish amid the hedge of flame [circumventi flamma exanimantur homines].”  It is usually supposed that these simulacra were hollow idols of basket-work.  But such would require to be constructed on an incredible scale for their limbs to be filled with men; and it is much more probable that they were spaces traced out upon the ground (like the Giant on the hill above Cerne Abbas in Dorset), and hedged in with the wattles to be fired.