Our supposition that the _gutuatri_ were a class of Druids is supported by classical evidence, which tends to show that the Druids were a great inclusive priesthood with different classes possessing different functions--priestly, prophetic, magical, medical, legal, and poetical. Cæsar attributes these to the Druids as a whole, but in other writers they are in part at least in the hands of different classes. Diodorus refers to the Celtic philosophers and theologians (Druids), diviners, and bards, as do also Strabo and Timagenes, Strabo giving the Greek form of the native name for the diviners, [Greek: ouateis], the Celtic form being probably _vátis_ (Irish, _fáith_).[1018] These may have been also poets, since _vátis_ means both singer and poet; but in all three writers the bards are a fairly distinct class, who sing the deeds of famous men (so Timagenes). Druid and diviner were also closely connected, since the Druids studied nature and moral philosophy, and the diviners were also students of nature, according to Strabo and Timagenes. No sacrifice was complete without a Druid, say Diodorus and Strabo, but both speak of the diviners as concerned with sacrifice. Druids also prophesied as well as diviners, according to Cicero and Tacitus.[1019] Finally, Lucan mentions only Druids and bards.[1020] Diviners were thus probably a Druidic sub-class, standing midway between the Druids proper and the bards, and partaking of some of the functions of both. Pliny speaks of "Druids and this race of prophets and doctors,"[1021] and this suggests that some were priests, some diviners, while some practised an empiric medical science. On the whole this agrees with what is met with in Ireland, where the Druids, though appearing in the texts mainly as magicians, were also priests and teachers. Side by side with them were the _Filid_, "learned poets,"[1022] composing according to strict rules of art, and higher than the third class, the Bards. The _Filid_, who may also have been known as _Fáthi_, "prophets,"[1023] were also diviners according to strict rules of augury, while some of these auguries implied a sacrifice. The Druids were also diviners and prophets. When the Druids were overthrown at the coming of Christianity, the _Filid_ remained as a learned class, probably because they had abandoned all pagan practices, while the Bards were reduced to a comparatively low status. M. D'Arbois supposes that there was rivalry between the Druids and the _Filid_, who made common cause with the Christian missionaries, but this is not supported by evidence. The three classes in Gaul--Druids, _Vates_, and Bards--thus correspond to the three classes in Ireland--Druids, _Fáthi_ or _Filid_, and Bards.[1024]