The moral which Diodorus draws from this is, that even among the wildest of barbarians the spirited principle of the soul yields to wisdom, and that Ares (the god of war) even there respects the Muses.

It is clear from this account that Diodorus had in mind the three classes of non-military professional men among the Celts, to whom other ancient writers also refer, namely, the Bards, the Seers, and the Druids.
His narrative is apparently an expansion, in the light of his reading and philosophical meditation, of information supplied by previous writers, notably Posidonius.

The latter, too, appears to have been Julius Caesar's chief authority, in addition to his own observation, but Caesar does not appear expressly to indicate the triple division here in question.

The account which he gives is important, and would be even more valuable than it is had he told us how far what he describes was written from his own personal information, and the degree of variation (if any) of religious practice in different districts.

However, Caesar's statements deserve the closest consideration.