fourth _Eclogue_ is of course out of the question; there is not a single
close parallel of the kind that Vergil usually permits himself to borrow
from his sources; we cannot even be sure that he had seen any of the
Sibylline oracles, now found in the third book of the collection,
which contains so strange a syncretism of Mithraic, Greek, and Jewish
conceptions, but we can no longer doubt that he was in a general way
well informed and quite thoroughly permeated with such mystical and
apocalyptic sentiments as every Gadarene and any Greek from the Orient
might well know. It speaks well for his love of Rome that despite these
influences it was he who produced the most thoroughly nationalistic epic
ever written.

The first fruit of Vergil's studies in evolutionary science at Naples was
the _Aetna_, if indeed the poem be his. The problem of the authorship
has been patiently studied, and the arguments for authenticity concisely
summarized by Vessereau[9] make a strong case. The evidence is briefly
this. Servius attributed the poem to Vergil in his preface and again in
his commentary on _Aeneid_, III, 578. Donatus also seems to have done so,
though some of our manuscripts of his _Vita_ contain the phrase _de qua
ambigitur_. Again, the texts of the _Aetna_ which we have agree also in
this ascription. Internal evidence proves the poem to be a work of the
period between 54 and 44, which admirably suits Vergilian claims. Its
close dependence upon Lucretius gives the first date, its mention of the
"Medea" of the artist Timomachus as being overseas, a work which was
brought to Rome between 46 and 44, gives the second. Finally, the _Aetna_
is by a student of Epicurean philosophy largely influenced by Lucretius.
It would be difficult to make a stronger case short of a contemporaneous
attribution. Has not Vergil himself referred to the _Aetna_ in the
preface of his _Ciris_, where he thanks the Muses for their aid in an
abstruse poem (l. 93)?