Virgil is a poet, not a lexicographer. This means he is more interested in the manipulation of language than in its precise meaning. This is certainly true of the poet’s use of the technical language of divination. As Nicholas Horsfall has argued, technical religious terminology constitutes a remarkably rich source of language in the Aeneid, but the poet’s use is more impressionistic than fastidious (Horsfall 1991: 149–150). This impressionism allows the poet to exploit the connotations of these terms for literary effect. Specifically the use of a particular term of divinatory art can indicate how a character within the poem reacts to and interprets a given omen. In this paper, I focus on the Waffenprodigium at Aen. 8.524–529, where there is thunder and lightning in a clear sky, a repeated trumpet blast, and the sight and sound of weapons clashing among the clouds. I argue that this omen should be interpreted in light of Aeneas’ decision to refer to it as portenta (Aen. 8.533), and that Aeneas’ positive explanation of the signs is undercut by his use of the term in a manner similar to James O’Hara’s pattern of the optimistic prophecy in which some unpleasant detail—very often a death—is omitted from a prophetic utterance, including the interpretation of omens (O’Hara 1990: 14–16, 54–60).
The term portentum, along with prodigium, denotes some event or manifestation that reveals a breach of the pax deorum that needs to be restored (Beard 1990: 31 with citations; North 1990 54–55). Apart from the instance in Aeneid 8, there are two other portenta in the Aeneid, and both manifest just such a breach of the pax deorum. The first portenta of the poem are the bees that swarm on the sacred laurel tree and the conflagration of Lavinia’s hair at Aen. 7.64–80. In this case the signs reveal that the intended marriage of Lavinia and Turnus amounts to a breach of the pax deorum, a fact confirmed by the prophecy of Faunus at Aen. 7.96–101. The last portenta occur in Book 11, where Diomedes is pursued by horribili uisu portenta (Aen. 11.271). These are his companions who have been transformed into birds as punishment for Diomedes’ attack on Venus at Troy (Aen. 11.275–277).
In light of these other two examples, the reader should be on guard against a superficially optimistic reading of the portenta in book 8. Such a reading is evident in Servius' gloss of portenta at Aen. 8.533 as bona omina, a gloss in keeping with (and probably deriving from) Aeneas’ own cheery interpretation of the signs. While the signs do in fact come from Venus and concern Aeneas’ new armour (Aen. 8.534–536), other elements in the scene indicate that the portenta are less cheery, and may even foretell the death of Pallas. The signs themselves are ambivalent: although the sounds of weapons are appropriate in the context of Venus’ delivery of Aeneas’ new armour, they also recall some of the omens following the assassination of Julius Caesar as recorded by Virgil at Geo. 1.474–475 (Mellinghoff-Bourgerie 1990: 77–78). Aeneas’ injunction to Evander not to ask what the signs mean (ne quaere, Aen. 8.532) recalls Anchises’ statement to Aeneas concerning Marcellus: o gnate, ingentem luctum ne quaere tuorum (Aen. 6.868). Importantly, that scene describes the untimely death of a young man who will be the hope of his people. Further echoes confirm the parallel. Just as Anchises apostrophises the Tiber in his eulogy of Marcellus (Aen. 6.873–874), so does Aeneas as he imagines the young men that will die in the war with the Latins (Aen. 8.538–540). Finally both Marcellus and Pallas are the “hope” of their peoples (see Aen. 6.875–876 and 8.514), raising issues of succession. These details confirm that the reader is meant to see the portenta here as signalling that the war will prove less happy than it might, especially for Pallas.